Can perineum stimulation feel pleasurable? | Some diary reports say yes [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 "perineum 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

Customers reported pleasure from perineum stimulation, alongside problems with comfort, movement, and electrical prototypes.

Mr. Okada proposed external pressure and vibration, while cautioning against forcing a chip when lubrication was lacking.

The current list includes some related products; the later custom stopper designs have no confirmed matches.

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: perineum stimulation

The OK Prostate Chip is a small device placed in the urethra (the urine passage) to act on the prostate. This topic concerns sensations around the perineum (the area behind the scrotum described in these entries). Mr. Okada links external pressure there with movement of a chip in the bulbar urethra (a wider part of the urine passage). He also describes attachments intended to transmit vibration through the chip.

Early linked chips offered perineum stimulation alongside bladder-entry warnings

In an entry published in January 2018, Mr. Okada announced linked and long models. He described the linked configuration with a 0-2mm gap as the easiest to handle. The linked design was at least 5cm long, and he warned that it could easily advance into the bladder.

He also described internal sensations responding to pressure from clothing, seats, and saddles. He warned of semen entering the bladder during ejaculation when a chip crossed the internal urinary sphincter (the bladder outlet muscle). Despite his comments about easy handling, Mr. Okada advised against the linked model for beginners unfamiliar with urethral anatomy.

(Source: ok-lab's diary, published January 2018)
https://ok-lab.hatenablog.com/entry/20180114/1515943724

Anal-chip attachments introduced perineal vibration with separate custom fitting charges

In an entry published in December 2018, Mr. Okada described an anal-chip attachment using one motor from a paired vibrator. He said it directly stimulated the perineum while sending gentler vibration through the whole chip. The custom attachment cost the vibrator's actual price plus ¥2,000 (about $13 at ¥156 = $1, rate as of 2026-09-04) excluding tax, as published in December 2018. Mr. Okada invited custom requests for the attachment.

(Source: ok-lab's diary, published December 2018)
https://ok-lab.hatenablog.com/entry/20181215/1544857573

Electrical testing connected with perineum stimulation caused concern for Mr. Okada

In an entry published in May 2019, Mr. Okada described health problems following low-frequency electrical tests. He reported an earlier episode he called heart failure, followed by 3 hours in bed.

During a later test, he reported an irregular heartbeat at volume 2 and 2 hours when he could not work. He questioned selling something he could no longer test. Mr. Okada concluded that he would never perform electrode (electrical contact) tests again.

(Source: ok-lab's diary, published May 2019)
https://ok-lab.hatenablog.com/entry/2019/05/04/162111

One custom trapezoid chip received positive feedback about perineum stimulation

In an entry published in September 2022, a customer reported on a custom assembly with a 15mm trapezoid-shaped support chip. The customer reported perineal pleasure and sensation extending toward the prostate.

The support chip was listed at ¥1,650 (about $11 at ¥156 = $1, rate as of 2026-09-04) in that report. Mr. Okada published the account but said he could not personally assess this unusual configuration.

(Source: ok-lab's diary, published September 2022)
https://ok-lab.hatenablog.com/entry/2022/09/10/122847

Rocking linked chips connected perineum stimulation with difficult retrieval risks

In an entry published in April 2024, Mr. Okada introduced a rocking linked pair connected by shape-memory wire (wire with spring-like elasticity). He described the connection as transmitting movement between the perineal end and the prostate end.

The design allowed all chip types at either end, with wire lengths of 3cm, 4cm, or 5cm. He warned that the approximately 10cm assembly could become difficult to retrieve by its central thread after entering the bladder. Mr. Okada advised medical assistance if that happened.

(Source: ok-lab's diary, published April 2024)
https://ok-lab.hatenablog.com/entry/2024/04/27/122924

Petal-frame tests showed that stronger perineum stimulation could become uncomfortable

In an entry published in May 2025, Mr. Okada compared versions of a petal frame (a chipless device with expanding wire sections). With 25mm petals, he ended one test after 3 hours because stimulation near the sphincter was too strong. He reported 24 hours without major discomfort in the opposite orientation, but still considered that size too stimulating for several days.

The published specification offered 15mm, 18mm, or 20mm petals, an overall length up to 15cm, and thread up to 35cm. The frame cost ¥7,000 (about $45 at ¥156 = $1, rate as of 2026-09-04) excluding tax, as published in May 2025. Mr. Okada considered roughly 20mm his upper guide around the sphincter, while saying suitable dimensions depended on the individual's anatomy.

(Source: ok-lab's diary, published May 2025)
https://ok-lab.hatenablog.com/entry/2025/05/24/122958

Apple-shaped stoppers combined perineum stimulation with difficult removal in testing

In an entry published in December 2025, Mr. Okada described an apple-shaped stopper for retention and stimulation in the bulbar urethra. He reported less strain but some movement with the separate version, compared with almost complete fixation in the integrated version. He warned that the integrated version could strain the urethra depending on its position, and both versions were difficult to remove.

Both versions cost ¥4,000 (about $26 at ¥156 = $1, rate as of 2026-09-04) excluding tax, as published in December 2025. A dedicated pusher (a tool intended to advance the stopper) cost ¥2,000 (about $13 at ¥156 = $1, rate as of 2026-09-04) excluding tax in the same entry. Mr. Okada cautioned that the 15mm stopper had not been tested for reliable retention.

(Source: ok-lab's diary, published December 2025)
https://ok-lab.hatenablog.com/entry/2025/12/20/123000

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The maker's answer to perineum stimulation

Mr. Okada proposed external pressure and vibration, but also described limits involving comfort, experience, and unwanted movement.

A separate battery pouch addressed movement while providing perineum pressure

In an entry published in January 2019, Mr. Okada replaced an earlier arrangement that clipped a vibrating chip's battery box to underwear. He reported accidental pulling when clothing moved and cable movement when the penis changed direction.

His revised arrangement used a separate fabric crotch pouch (a pocketed cloth support) for the battery box. He said sitting produced slight pressure on the perineum, with stimulation continuing even when the vibration was off. Mr. Okada proposed the pouch for battery storage.

(Source: ok-lab's diary, published January 2019)
https://ok-lab.hatenablog.com/entry/20190105/1546673405

A pressure belt was suggested as an alternative for perineum stimulation

In an entry published in February 2020, a customer reported sustained stimulation from the pressure of tight swimming trunks. The customer had not compared those trunks with another swimsuit style.

Mr. Okada replied that, in his view, pressure on the perineum amplified sensitivity. He named the company's pressure belt and ordinary thong underwear as possible alternatives to the swimming trunks.

(Source: ok-lab's diary, published February 2020)
https://ok-lab.hatenablog.com/entry/2020/02/01/151232

Mr. Okada limited his perineum stimulation claims to experienced holder users

In an entry published in October 2023, Mr. Okada tested a sideways retaining gate (an external chip-retaining part) with the 2017 downward holder. He reported improved stability compared with arrangements where the chip shifted and became difficult to reposition. He reported bleeding around the rim of his penis head during prolonged belt use, attributing it to friction.

He said the retaining gate's silicone tubing could soften contact with that rim. His comments followed only a few days of testing. Mr. Okada cautioned that people unfamiliar with downward holders were unlikely to obtain the experience he described easily.

(Source: ok-lab's diary, published October 2023)
https://ok-lab.hatenablog.com/entry/2023/10/21/123054

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 perineum stimulation changed over time

The diary does not say what the current state is.

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OK Prostate Chip products related to perineum stimulation

The current list includes a glass chip and fabric supports from these accounts.

Products that appear in these entries

(Source: ok-lab's diary, published January 2019)
https://ok-lab.hatenablog.com/entry/20190105/1546673405

(Source: ok-lab's diary, published November 2019)
https://ok-lab.hatenablog.com/entry/2019/11/09/132111

(Source: ok-lab's diary, published October 2023)
https://ok-lab.hatenablog.com/entry/2023/10/21/123054

Products the diary mentioned as alternatives

(Source: ok-lab's diary, published February 2020)
https://ok-lab.hatenablog.com/entry/2020/02/01/151232

Historical configurations include the linked pair, anal-chip vibrator attachment, electrical prototypes, trapezoid assembly, rocking pair, and sideways retaining gate. They also include the shoulder-supported vibrator, custom perineal motor, gourd-shaped frame, ceramic garment prototype, petal frame, apple stopper, and dedicated pusher. No matching product can be confirmed on the current list.

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Common worries about perineum stimulation

The diary's questions concern unexpected fluid, uneven sensation, and comfort after a chip moves.

"What was the fluid released during perineum stimulation?"

In an entry published in December 2018, a customer asked about an unexplained release of fluid during perineal massage. They described a large amount that had not appeared again.

Mr. Okada said he found it difficult to imagine 100cc of penile discharge being anything other than urine. That quantity appeared in his reply; the customer did not describe a measurement. Mr. Okada encouraged the customer to value the pleasurable experience, although the diary records no confirmation of the fluid's identity.

(Source: ok-lab's diary, published December 2018)
https://ok-lab.hatenablog.com/entry/20181222/1545459719

"Why did the electrical pad dominate perineum stimulation?"

In an entry published in May 2019, an electrode-chip tester reported bleeding during an unsuccessful attempt, followed later by successful placement. The tester felt stimulation only at the perineal pad and asked about separating an earlier prototype's components.

Mr. Okada attributed the difference to greater sensitivity at the pad's location, rather than its size. He offered another urethral-only prototype instead; the diary does not record its subsequent effect. Mr. Okada also offered cancellation to customers concerned by the report.

(Source: ok-lab's diary, published May 2019)
https://ok-lab.hatenablog.com/entry/2019/05/04/162111

"Can perineum stimulation still feel good when a chip shifts?"

In an entry published in November 2019, a single-glass-chip customer wanted longer retention after a pleasurable experience ended with movement during urination. The customer stopped further attempts because the perineal skin was sore, and asked which chip might remain in place longer.

Mr. Okada mentioned longer, curved, and linked designs, but said movement during urination could still occur. He said a chip in the bulbar urethra could provide pleasure comparable to perineal stimulation. The diary does not record which replacement the customer chose or how it felt. Mr. Okada advised against forcing the chip when lack of lubrication made movement difficult.

(Source: ok-lab's diary, published November 2019)
https://ok-lab.hatenablog.com/entry/2019/11/09/132111

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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.