![Can a chip stimulate both seminal vesicles? | No best shape is established [OK Prostate Chip]](/img/a/T0581/eyecatch.svg)
This page is based on entries from "ok-lab's diary" (https://ok-lab.hatenablog.com/), the Japanese development diary written by Mr. Okada, founder of OK Lab, a small company in Japan (Okada Comfortable Life Laboratory). Only the entries about "shapes intended for seminal vesicle stimulation" are summarized here, in order of publication. Past prices and sizes are as written at the time. Current prices come from the official product list (retrieved September 4, 2026). Quotations are translated from Japanese.
Note: This page is a personal reading log by someone with no connection to the maker or the seller. It reflects the source entries as of their publication dates and makes no guarantee of accuracy or safety. The product is not a medical device; talk to a doctor about any health decision. Check the official site for current information. This page contains advertising.
In short
- Mr. Okada reports uneven stimulation and safety problems across designs intended to press near the seminal vesicles.
- His responses included revised shapes, a withheld launch, and repairs after wire failures.
- Related standard products remain listed, but the latest custom proposal has no recorded customer test result.
If you see blood in your urine, even a small amount or for the first time, do not wait and see. See a urologist right away. If you suddenly cannot urinate, or the device cannot be removed, do not try to fix it yourself. Go to a medical facility, including emergency care, immediately.
About this product
The OK Prostate Chip is a small device that is placed in the urethra (the urine passage) so that it acts on the prostate; the maker sells it in several shapes, sizes and materials. It is made and sold by OK Lab (Okada Comfortable Life Laboratory), a small company in Japan, through its own online store, and prices are in Japanese yen (JPY). The maker's development diary, "ok-lab's diary", is written in Japanese. This page is an English summary of it, and every quotation is translated. OK Lab ships internationally, so readers outside Japan can order (see "Buying from outside Japan" below). Product names on this page are plain-English descriptions. The official Japanese product name is shown once in the product table so you can find the same item in the store.
Before you read: key terms
| Term | Plain-English meaning |
|---|---|
| Urethra | The urine passage; it carries urine and is where the base device is placed. |
| Prostate | The body structure targeted by the base chip. Its biological role: The diary does not explain this. |
| Seminal vesicles | Paired structures behind the bladder, described in the diary as storing seminal fluid; these designs aim to apply pressure nearby. |
| Rectal chip | A separate device placed through the anus into the bowel, intended to apply pressure toward the prostate or seminal vesicles. |
| Anal sphincter | The muscle ring at the anus, discussed as affecting movement and external control of rectal chips. |
| Internal urethral sphincter | A muscle ring at the bladder entrance, used by Mr. Okada as a landmark for the intended pressure area. |
| Shape-memory wire | Flexible wire that returns toward a preset shape; it connects sections and provides spring force. |
| Bladder loop | The loop at a device's bladder end, intended for bladder stimulation. |
| Petal loops | Small side loops attached at rubber-covered joints, used as stops or added pressure features. |
| Prostatitis | Prostate inflammation; its role here is a customer's report of a problem after repeated use. |
What happens: seminal vesicle stimulation
The OK Prostate Chip is a small device placed in the urethra (the urine passage) to act on the prostate. These entries also describe rectal chips (separate bowel-side devices) intended to press near the seminal vesicles (paired structures behind the bladder). Mr. Okada describes pressure from the bowel side in earlier work and from inside the bladder in later work. His reports include uneven pressure, uncertain results, and designs that raised safety concerns.
Custom lengths were offered for seminal vesicle stimulation in August 2018
In an entry published in August 2018, Mr. Okada introduced rectal designs with different intended targets. A 90mm version targeted the seminal vesicles; a 110mm version targeted both the prostate and seminal vesicles. The new product was listed at ¥6,000, (about $38 at ¥156 = $1, rate as of 2026-09-04) tax excluded, as published that month. Mr. Okada offered specified lengths through custom orders.
(Source: ok-lab's diary, published August 2018)
https://ok-lab.hatenablog.com/entry/20180825/1535182626
Straight designs did not meet Mr. Okada's seminal vesicle stimulation aims
In an entry published in September 2018, Mr. Okada described a substantially curved bowel-side design. He concluded that the portion beyond 10cm needed a pronounced bend. In his view, a nearly straight instrument could not provide the stimulation he wanted. He proposed separate shapes for devices extending farther into the bowel and those remaining mainly in its lower portion.
(Source: ok-lab's diary, published September 2018)
https://ok-lab.hatenablog.com/entry/20180915/1536986152
One-sided pressure prompted another prototype for seminal vesicle stimulation
In a later entry published in September 2018, Mr. Okada reported that a longer bowel-side chip pressed only his left seminal vesicle. He described no stimulation on the right. He made a dedicated prototype, but explicitly said its effect had not yet been measured. His proposed answer was a tip intended to distribute pressure across both sides.
(Source: ok-lab's diary, published September 2018)
https://ok-lab.hatenablog.com/entry/20180922/1537592180
A narrowed rectal chip carried custom pricing for seminal vesicle stimulation
In an entry published in November 2018, a narrowed rectal design was described as dedicated to seminal vesicle stimulation. Its listed dimensions were about 12cm long, 4cm or 6cm wide, with a lower width of 3cm.
The published base price was ¥7,000, (about $45 at ¥156 = $1, rate as of 2026-09-04) tax excluded, for the 4cm version. Custom pricing added ¥350 (about $2 at ¥156 = $1, rate as of 2026-09-04) per 1cm of extra resin plate. Mr. Okada directed requests for other specifications to custom ordering.
(Source: ok-lab's diary, published November 2018)
https://ok-lab.hatenablog.com/entry/20181123/1542963370
A customer reported inflammation after repeated use for seminal vesicle stimulation
In an entry published in March 2019, a customer described the hook-shaped rectal chip as reaching an unfamiliar area. The customer guessed this was the seminal vesicles, then reported prostatitis (prostate inflammation), possibly from repeated use. The message described disrupted sleep and a break of about 1 month. Mr. Okada acknowledged the account; the diary records no treatment advice or later recovery report for this customer.
(Source: ok-lab's diary, published March 2019)
https://ok-lab.hatenablog.com/entry/2019/03/02/151104
Greater depth reduced Mr. Okada's reported seminal vesicle stimulation
In an entry published in May 2024, Mr. Okada discussed trials using spring-connected chips longer than 10cm. Their shape-memory wire (wire that returns toward a preset shape) supplied spring force.
He attributed the sensation to an area 1–2cm from the internal urethral sphincter (the muscle ring at the bladder entrance). He reported almost no sensation farther inside the bladder. Mr. Okada cautioned that strong pressure could involve unknown health problems.
(Source: ok-lab's diary, published May 2024)
https://ok-lab.hatenablog.com/entry/2024/05/04/122911
A vibrating prototype raised health concerns during seminal vesicle stimulation
In an entry published in May 2024, Mr. Okada described testing a curved vibrating prototype. After about 5–10 minutes, he reported that his heart felt abnormal and stopped the vibration. He wrote that he did not intend to resume vibrating it.
Making that prototype had taken about 5 days. Mr. Okada said sales could not begin unless he found a more efficient manufacturing method. He instead proposed exploring a similar shape without vibration.
(Source: ok-lab's diary, published May 2024)
https://ok-lab.hatenablog.com/entry/2024/05/11/122910
Two ear loops became the bladder mouse's proposed answer
In an entry published in May 2025, Mr. Okada introduced a two-eared bladder-loop design (bladder mouse). A bladder loop (a loop intended for bladder stimulation) formed its central feature.
He said the ordinary loop missed the seminal vesicles, while the earlier S-shaped device could press only one side. The added ears were intended to address both sides. The entry listed ¥4,000 (about $26 at ¥156 = $1, rate as of 2026-09-04) for the basic loop, ¥2,000 (about $13 at ¥156 = $1, rate as of 2026-09-04) for two ears, and ¥6,000 (about $38 at ¥156 = $1, rate as of 2026-09-04) for the combined design, tax excluded. Mr. Okada said its dimensions still needed investigation and offered builds to order.
(Source: ok-lab's diary, published May 2025)
https://ok-lab.hatenablog.com/entry/2025/05/10/122936
A trapped cable complicated Mr. Okada's account of seminal vesicle stimulation
In the entry published in May 2025, Mr. Okada recounted a caller whose vibrating-device cable could not be removed from the bladder. He reported about 30cm of cable inside and suspected tangling.
He speculated about pressure near the seminal vesicles. The customer later placed further orders, but the diary does not record how the incident ended. Mr. Okada advised medical attention.
(Source: ok-lab's diary, published May 2025)
https://ok-lab.hatenablog.com/entry/2025/05/10/122936
The maker's answer to seminal vesicle stimulation
Mr. Okada revised designs and withdrew earlier claims when their limits became apparent.
Early claims about seminal vesicle stimulation needed explicit corrections
In an entry published in September 2018, a reader challenged the idea that a central tip could directly press both seminal vesicles. The reader argued that a forked tip was needed because the structures were separate. Mr. Okada welcomed the suggestion and considered a future dedicated design.
He also withdrew his earlier claim that the rectal design needed no bowel cleansing. He corrected the external-control claim: a device entirely beyond the anal sphincter could not be controlled from outside. His revised account limited such control to a tip remaining at the anal sphincter (the muscle ring at the anus).
(Source: ok-lab's diary, published September 2018)
https://ok-lab.hatenablog.com/entry/20180901/1535779541
Removal concerns halted the narrowed design for seminal vesicle stimulation
In an entry published in December 2018, Mr. Okada put the narrowed rectal model's launch on hold after his own removal experience caused alarm. He ultimately removed it but did not want customers facing the same uncertainty. He described easier retrieval with the standard hook-shaped model. Mr. Okada emphasized understanding a device's shape.
(Source: ok-lab's diary, published December 2018)
https://ok-lab.hatenablog.com/entry/20181201/1543652709
The S-shaped design added a covered connection for seminal vesicle stimulation
In an entry published in May 2024, Mr. Okada described an S-shaped assembly whose bladder-side tip curved toward the back. The published tax-excluded section prices were ¥3,000 (about $19 at ¥156 = $1, rate as of 2026-09-04) for the bladder section, ¥3,000 (about $19 at ¥156 = $1, rate as of 2026-09-04) for the prostate section, and ¥2,000 (about $13 at ¥156 = $1, rate as of 2026-09-04) for the lower section.
Connection cost ¥4,000 (about $26 at ¥156 = $1, rate as of 2026-09-04), and the tube cover cost ¥1,000 (about $6 at ¥156 = $1, rate as of 2026-09-04); the stated total was ¥13,000, (about $83 at ¥156 = $1, rate as of 2026-09-04) tax excluded. Changes to the standard lengths or angles required custom fees. Mr. Okada recommended the wire cover because he considered bare wire uncomfortable at the sensitive inner muscle ring.
(Source: ok-lab's diary, published May 2024)
https://ok-lab.hatenablog.com/entry/2024/05/18/122913
Petal-loop failures affected parts also discussed for the bladder mouse
In an entry published in August 2025, a customer reported a petal-loop attachment (a small side-loop joint) separating after about 2 weeks. A second multi-loop device then lost both side loops; the customer reported that exposed internal wire cut the lining. OK Lab repaired the first device, and the customer confirmed receiving it before arranging another repair.
Mr. Okada initially considered ending sales if failures increased, then described a revised attachment using unbent wire and a larger rubber joint. He kept the published price at ¥1,000 (about $6 at ¥156 = $1, rate as of 2026-09-04) per petal. OK Lab asked the customer to return faulty items for inspection and repair.
(Source: ok-lab's diary, published August 2025)
https://ok-lab.hatenablog.com/entry/2025/08/30/122943
If you see blood in your urine, even a small amount or for the first time, do not wait and see. See a urologist right away. If you suddenly cannot urinate, or the device cannot be removed, do not try to fix it yourself. Go to a medical facility, including emergency care, immediately.
How seminal vesicle stimulation changed over time
| Published | What the diary said then |
|---|---|
| Oct 2018 | A split-tip example measured 11cm long and about 5cm across; Mr. Okada preferred smaller. |
| Dec 2018 | Mr. Okada found no clear sensation or fluid-quantity gain from the stronger 6cm prototype. |
| May 2024 | Standard S-shaped sections measured 20mm, 25mm, and 25mm. |
| May 2025 | Four ear loops prevented placement in Mr. Okada's trial; two worked. |
| May 2025 | Mr. Okada reported inconsistent stimulation with approximately 50mm ears. |
| Aug 2025 | A roughly 25cm bowel-side prototype produced mild massage but no released fluid, he reported. |
OK Prostate Chip products related to seminal vesicle stimulation
The current list includes a related rectal model and a ceramic component used in spring-connected assemblies.
Products that appear in these entries
| Product (official name) | Price incl. tax | Relation to this topic |
|---|---|---|
| Hook-shaped resin rectal chip (OKプロステートお尻チップ 樹脂素材尸の字型) | ¥7,700 (about $49 at ¥156 = $1, rate as of 2026-09-04) | In March 2019, a customer described this rectal model while reporting inflammation after repeated use. |
| Short ceramic chip (OKプロステートチップ 陶器素材ショートタイプ) | ¥3,300 (about $21 at ¥156 = $1, rate as of 2026-09-04) | In May 2024, this formed the lower component of a spring-connected trial that Mr. Okada described as comfortable in position. |
(Source: ok-lab's diary, published March 2019)
https://ok-lab.hatenablog.com/entry/2019/03/02/151104
(Source: ok-lab's diary, published May 2024)
https://ok-lab.hatenablog.com/entry/2024/05/04/122911
Products the diary mentioned as alternatives
The diary names no alternative.
For the early custom rectal designs, narrowed model, spring-connected assemblies, S-shaped device, bladder mouse, and custom vibrating builds:
No matching product can be confirmed on the current list.
Common worries about seminal vesicle stimulation
The customer exchanges leave prolonged comfort and the best custom shape unresolved.
"Is the bladder mouse suitable for prolonged use?"
In an entry published in June 2025, a customer requested a custom wire-loop assembly for prolonged use and asked about possible problems. Staff replied that they saw no obviously unsuitable feature. Mr. Okada added that he had not tested prolonged use of that design.
The diary presents the completed build but records no customer's experience with prolonged use. Mr. Okada cautioned that seminal vesicle stimulation might become uncomfortable.
(Source: ok-lab's diary, published June 2025)
https://ok-lab.hatenablog.com/entry/2025/06/28/122915
"Can OK Lab choose a seminal vesicle stimulation design?"
In an entry published in February 2026, a customer asked OK Lab to choose the parts for a movable vibrating device. Staff proposed a longer tip of about 5cm with a stronger angle. Mr. Okada said the customer's device was made but that he had not tested it himself.
The diary does not record how it felt for the customer. Mr. Okada emphasized that the most suitable shape was not known.
(Source: ok-lab's diary, published February 2026)
https://ok-lab.hatenablog.com/entry/2026/02/21/122935
"What did a custom seminal vesicle stimulation vibrator cost?"
In an entry published in March 2026, a customer requested the previously described longer-tip design with a movable connection. The quotation listed ¥6,600 (about $42 at ¥156 = $1, rate as of 2026-09-04) for the vibrating tip with an 8mm motor and ¥4,400 (about $28 at ¥156 = $1, rate as of 2026-09-04) for the small movable connection. It also listed ¥550 (about $4 at ¥156 = $1, rate as of 2026-09-04) for the requested USB connection change.
The quotation applied to that custom request. The diary does not record whether this order was completed or how the device felt in use.
(Source: ok-lab's diary, published March 2026)
https://ok-lab.hatenablog.com/entry/2026/03/07/122907
Buying from outside Japan
OK Lab ships internationally to countries covered by Japan Post's EMS courier service. Overseas orders are paid in advance by PayPal. Each order carries a ¥400 (about $3 at ¥156 = $1, rate as of 2026-09-04) handling fee, and EMS shipping is charged on top. These terms come from OK Lab's official sales-terms page (written here as plain text, not a link: ok-lab.net/docs/law), checked on September 7, 2026; confirm them on the official store before you order, because they can change.
Summary of this article
| What you wanted to know | The answer |
|---|---|
| What is the short answer? | Intended pressure targets do not establish a best shape; problems and unanswered questions remain. |
| What is the product? | A Japanese device family from OK Lab, with separate rectal designs also discussed here. |
| What do the terms mean? | The diary distinguishes bowel-side devices, bladder-side loops, flexible connections, and paired target structures. |
| What happened in testing? | Mr. Okada reported uneven effects; the accounts also include inflammation, heart symptoms, and a trapped cable. |
| What did the maker change? | Claims, shapes, launch plans, and loop attachments were revised. |
| How did designs change? | Split rectal tips were followed by S-shaped assemblies, ear loops, and further custom designs. |
| Which current products relate? | A standard rectal model and a short ceramic component appear on the supplied list. |
| What remains unanswered? | The customer exchanges do not establish prolonged comfort or the best custom vibrating shape. |
| How are overseas orders handled? | Advance PayPal payment, a ¥400 (about $3 at ¥156 = $1, rate as of 2026-09-04) handling fee, and additional EMS shipping apply under the supplied terms. |
Source: ok-lab's diary (Okada Comfortable Life Laboratory). The original entries are in Japanese; quotations on this page are translated. Photos and videos are on the original entries.
This article is a summary of the maker's development diary. The product is not a medical device and no result is guaranteed. If anything feels wrong or worries you, see a doctor. Prices, specifications and cautions change, so confirm the latest information on the official blog and the official site. Questions about ordering and shipping go to the seller.