Can the OK Prostate Chip stimulate seminal vesicles? | The maker reports effects and serious problems [OK Prostate Chip]

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 "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.

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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

The maker attributes some sensations to seminal vesicle pressure; reports also describe bleeding and difficult removal.

Mr. Okada proposed different designs but also withheld products and warned about prolonged exposure.

The current product list includes the short ceramic chip used as a supporting component in a linked assembly.

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.

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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.

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Before you read: key terms

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What happens: seminal vesicle stimulation

The OK Prostate Chip is a small urethral device intended to act on the prostate. The diary describes seminal vesicles (paired structures behind the bladder) as targets for pressure intended to produce sensations or release fluid. Its reports discuss pressure from the rectum (the bowel area beside them) and, later, from devices within the bladder. These explanations belong to Mr. Okada and his correspondents.

Seminal vesicle stimulation reports included bleeding and painful removal with a custom chip

In an entry published in January 2018, a customer explored sensations using a custom short chip. After about 12 hours, they reported darker urine, which they attributed to bleeding. Repeated use brought visible blood on the chip, pain, and blood in the next ejaculate.

They also reported unsuccessful removal attempts and pain when the attached thread was pulled. Their 25cm thread was too short; an added note said lengths of 25cm or more could be specified when ordering. Mr. Okada favored brief initial exposure because neither glass nor epoxy resin (a chip-making material) eliminated friction.

(Source: ok-lab's diary, published January 2018)
https://ok-lab.hatenablog.com/entry/20180118/1516263011

Mr. Okada linked the longer U-turn chip to possible seminal vesicle stimulation

An entry published in October 2018 priced the single-lobe U-turn rectal chip at ¥5,000 (about $32 at ¥156 = $1, rate as of 2026-09-04) tax excluded. Its dimensions were 9.5cm overall, 6cm inside the bowel, and 35mm at the widest point. The longer model measured 11cm overall, 8cm inside, and 35mm wide; Mr. Okada said it could partly stimulate the seminal vesicle area. He also warned about displacement of the surrounding cover and recommended external support.

(Source: ok-lab's diary, published October 2018)
https://ok-lab.hatenablog.com/entry/20181031/1540960147

A seminal vesicle stimulation report described prostate inflammation after repeated use

In an entry published in March 2019, a customer reported prostate inflammation after repeated use of a hooked rectal chip. They associated an unfamiliar sensation with the seminal vesicles, but also described throbbing at bedtime that disrupted sleep. They suspected overuse and reported pausing use for about 1 month. Mr. Okada thanked them and requested permission to publish the account; the diary does not record whether their symptoms resolved.

(Source: ok-lab's diary, published March 2019)
https://ok-lab.hatenablog.com/entry/2019/03/02/151104

A seminal vesicle vibrator test ended after Mr. Okada reported heart problems

In an entry published in May 2024, Mr. Okada reported a sudden heart problem after roughly 5–10 minutes testing a dedicated vibrator prototype. He stopped the vibration and eventually removed the device. He also wrote that one prototype took about 5 days to make, leaving commercial production unresolved. Because of his existing heart condition, Mr. Okada said he did not intend to resume its powered vibration.

(Source: ok-lab's diary, published May 2024)
https://ok-lab.hatenablog.com/entry/2024/05/11/122910

Paired loops aimed to address one-sided seminal vesicle stimulation

An entry published in May 2025 introduced a paired-ear bladder-loop assembly (bladder mouse). Mr. Okada described it as an attempt to address both seminal vesicles, unlike his earlier three-part bladder-side chip (Alien). He said that earlier design could, at best, press effectively on one side.

The published price was ¥4,000 (about $26 at ¥156 = $1, rate as of 2026-09-04) tax excluded for the plain bladder loop, plus ¥2,000 (about $13 at ¥156 = $1, rate as of 2026-09-04) tax excluded for the paired ears. Mr. Okada cautioned that suitable ear dimensions, angles, and directions still needed investigation.

(Source: ok-lab's diary, published May 2025)
https://ok-lab.hatenablog.com/entry/2025/05/10/122936

Mr. Okada reported mild seminal vesicle massage without fluid release

In an entry published in August 2025, Mr. Okada described a large, long rectal wire-loop design intended for seminal vesicle massage. He reported that it could not produce the pressure needed for fluid release, attributing this limitation to its lightweight construction. The published price was ¥9,000 (about $58 at ¥156 = $1, rate as of 2026-09-04) tax excluded, plus ¥6,000 (about $38 at ¥156 = $1, rate as of 2026-09-04) tax excluded for the massage cross-loop (crossing wire loops). Mr. Okada specified the crossing arrangement as necessary for the massage effect he intended.

(Source: ok-lab's diary, published August 2025)
https://ok-lab.hatenablog.com/entry/2025/08/02/123058

Flexible connections brought new pricing and cautions for seminal vesicle stimulation

An entry published in February 2026 described a flexible vibrator assembly linking a motor and ceramic chip. Mr. Okada proposed that its curved section could direct pressure toward the seminal vesicles from inside the bladder. He also thought vibration through the bladder wall might contribute.

The additional flexible-connection charge was ¥4,000 (about $26 at ¥156 = $1, rate as of 2026-09-04) tax excluded for short or semilong ceramic chips, above the existing vibrator price. For extended or long ceramic chips, the additional charge was ¥5,000 (about $32 at ¥156 = $1, rate as of 2026-09-04) tax excluded. Mr. Okada cautioned that prolonged bladder vibration might be harmful, after finding the ceramic tip seemed to vibrate more strongly than the motor.

(Source: ok-lab's diary, published February 2026)
https://ok-lab.hatenablog.com/entry/2026/02/14/121602

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The maker's answer to seminal vesicle stimulation

Mr. Okada's responses included cushioning concepts, postponed releases, supporting components, and cautions about prolonged exposure.

Mr. Okada proposed water cushioning to vary seminal vesicle stimulation

An entry published in October 2018 described a rectal chip surrounded by water inside a condom. Mr. Okada intended the water-filled cover to separate bowel expansion from pressure generated by the chip. His proposal used chip shape and size to vary the strength of seminal vesicle stimulation. He also cautioned that larger arrangements could rupture the cover and might require stronger material.

(Source: ok-lab's diary, published October 2018)
https://ok-lab.hatenablog.com/entry/20181020/1540018080

Removal concerns delayed a narrowed-neck design intended for seminal vesicle stimulation

In an entry published in December 2018, Mr. Okada described testing a 6cm narrowed-neck hooked rectal prototype. He reported difficulty removing it and said the experience briefly alarmed him. He found a standard 5cm hooked design easier to remove while producing a similar amount of fluid. Mr. Okada put the narrowed-neck version's launch on hold because he did not want customers to experience that alarm.

(Source: ok-lab's diary, published December 2018)
https://ok-lab.hatenablog.com/entry/20181201/1543652709

Mr. Okada recommended a ceramic supporting chip for seminal vesicle stimulation assemblies

In an entry published in May 2024, Mr. Okada described assemblies using shape-memory wire (wire that returns to a formed curve). Among his examples, a short ceramic chip supported a second chip whose tip he described as remaining partly inside the bladder. He associated these linked designs with pressure toward the seminal vesicles from the bladder side. Mr. Okada recommended the short ceramic chip as a supporting component when stability was the aim.

(Source: ok-lab's diary, published May 2024)
https://ok-lab.hatenablog.com/entry/2024/05/04/122911

A new bladder-side design launched with cautions about prolonged seminal vesicle stimulation

In an entry published in May 2024, Mr. Okada decided to begin selling the three-part bladder-side chip. He acknowledged that he still did not fully understand its effects and found it physically draining. He distinguished its demands from those of his earlier prostate-focused chips. Mr. Okada cautioned against sleeping with it or wearing it continuously for days until users were accustomed to it and confident about their response.

(Source: ok-lab's diary, published May 2024)
https://ok-lab.hatenablog.com/entry/2024/05/18/122913

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.

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How seminal vesicle stimulation changed over time

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OK Prostate Chip products related to seminal vesicle stimulation

The short ceramic chip appears as a supporting component in a linked assembly discussed by Mr. Okada.

Products that appear in these entries

(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.

The custom short chip, unspecified historical urethral and rectal variants, three-part bladder-side chip, and later specialized loop or flexible-vibrator assemblies are discussed above.

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Common worries about seminal vesicle stimulation

Reader questions focused on absent sensations, differences between devices, and prolonged use.

"Will stronger seminal vesicle stimulation help when nothing feels different?"

An entry published in November 2018 describes a customer who felt no stimulation from a two-lobe U-turn rectal chip. Mr. Okada replied that prostate and seminal vesicle sensations could differ, while anatomy could prevent the chip reaching the intended area. He said he was withholding a dedicated seminal vesicle design from sale because he considered it too risky.

A linked follow-up published in December 2018 records continued lack of pleasure and concern about snagging during removal. Mr. Okada then offered a special custom version; the diary does not record whether the customer accepted. His November advice was against buying a larger size simply because the existing chip produced no sensation.

(Source: ok-lab's diary, published November 2018)
https://ok-lab.hatenablog.com/entry/20181117/1542436271

(Source: ok-lab's diary, published December 2018)
https://ok-lab.hatenablog.com/entry/20181201/1543652709

"Could seminal vesicle stimulation explain a different feeling with sounds?"

In an entry published in May 2024, a customer asked why a semilong chip lacked a sensation experienced with a urethral sound (a urine-passage instrument). Mr. Okada said he did not fully understand the sensation described, but suspected stimulation near the seminal vesicles. He also thought a sound could apply pressure more directly than a chip left in place.

The diary does not record a subsequent change of device. Mr. Okada suggested the three-part bladder-side chip as a possible alternative only if his explanation matched the customer's experience.

(Source: ok-lab's diary, published May 2024)
https://ok-lab.hatenablog.com/entry/2024/05/25/122919

"Has prolonged seminal vesicle stimulation been tested with bladder loops?"

An entry published in June 2025 records a customer requesting a custom paired-ear bladder-loop assembly for prolonged use. Staff initially said they saw nothing obviously unsuitable for that purpose. The diary shows the completed assembly but does not record the customer's experience with prolonged use. Mr. Okada qualified the staff response: he had not tested prolonged wear and cautioned that the stimulation might become distressing.

(Source: ok-lab's diary, published June 2025)
https://ok-lab.hatenablog.com/entry/2025/06/28/122915

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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.

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Summary of this article

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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.