Will an unglazed ceramic chip feel rough? | The diary reports friction, injury, and changing sensations [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 (Okada Comfortable Life Laboratory). Only the entries about "roughness of unglazed ceramic" 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

Unglazed ceramic felt rough in the diary accounts, which included injury and bleeding.

OK Lab, a small company in Japan, described coating requirements and warned against copying rough ceramic experiments.

The current list includes ceramic models; the rough finishes discussed here belonged to custom requests and tests.

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: rough ceramic chips

The OK Prostate Chip is a small device placed inside the urethra so that it acts on the prostate. These entries discuss rough surfaces on ceramic versions, including an uncoated thread-hole area and experimental finishes intended to increase friction. That surface is part of the chip itself and comes into contact with the inside of the urine passage. Mr. Okada's accounts describe both strong initial sensations and problems, including injury.

An unglazed ceramic thread hole had a dull, rough finish

In an entry published in June 2019, a customer asked why the ceramic chip's thread hole would lack glaze (a surface coating). Mr. Okada compared the exposed area with the rough, unglazed foot underneath a tea bowl. He explained that glazing the entire chip would make it stick to the kiln or shelf during firing (heating in the kiln).

The hole therefore provided an unglazed support point while the chip was suspended for firing. The diary does not record whether the customer received this custom chip or how it felt in use. Mr. Okada initially required a resin coating over the hole, then offered uncoated supply if the customer accepted that finish.

(Source: ok-lab's diary, published June 2019)
https://ok-lab.hatenablog.com/entry/2019/06/01/155432

Rough ceramic chips prompted Mr. Okada to seek care for injury

In an entry published in June 2019, Mr. Okada reported a urethral injury associated with his rough ceramic experiments and a visit to a urologist. He wrote that the doctor examined the roughened chip by touch and told him it was dangerous and that he should stop. The account concerns a chip with its glaze altered, rather than simply an unfinished thread hole.

Mr. Okada also described testing a mechanically roughened ceramic chip that remained inside the urethra. He felt the friction was suitable near the prostate but excessive at the internal urethral sphincter, whose function these entries do not explain. He warned against prolonged contact there and against copying his rough ceramic experiments.

(Source: ok-lab's diary, published June 2019)
https://ok-lab.hatenablog.com/entry/2019/06/15/144142

A rough ceramic chip request received a restricted custom finish

In an entry published in June 2019, a customer requested an enlarged curved ceramic chip with a rough finish. Mr. Okada delayed replying because the request arrived just after his injury, when he felt he could only refuse. He later reported a day-long test without a particular problem, after a week's break, and decided to make the requested item.

He restricted the rough finish to the enlarged sections, aiming to avoid continuous contact with the sphincter. He suspected that a narrow section held at a forced angle could injure that structure. His eventual offer was explicitly at the customer's own risk; the diary does not record that customer's experience with the finished chip.

(Source: ok-lab's diary, published June 2019)
https://ok-lab.hatenablog.com/entry/2019/06/22/123034

An unglazed porcelain chip arrived with its maker's bleeding report

In an entry published in October 2020, a customer sent Mr. Okada a handmade white porcelain chip inspired by his ceramic products. The sender described it as fired without glaze and said their own use of an unglazed chip had caused a little bleeding. They proposed nail polish as a surface covering; this suggestion came from the sender.

The enclosed sample was described as unused, so the bleeding report was not an account of Mr. Okada's test. Mr. Okada welcomed the sample and expressed interest in its texture, but this entry contains no result from his own use. His response was that he intended to test it and report back.

(Source: ok-lab's diary, published October 2020)
https://ok-lab.hatenablog.com/entry/2020/10/03/121700

Unglazed porcelain friction faded during Mr. Okada's later test

In an entry published in October 2020, Mr. Okada reported testing the handmade chip, measuring 40 mm long and approximately 8 mm wide. He attributed its difficult passage to strong friction and reported about 5 minutes before it reached the prostate. He also said it was difficult to pass during urination.

After a short time, however, he felt almost no friction or stimulation. He suspected moisture inside the urethra had formed a covering over the surface, making it slippery. Mr. Okada qualified his assessment by saying prolonged use remained untested and its effect on the sphincter was unknown.

(Source: ok-lab's diary, published October 2020)
https://ok-lab.hatenablog.com/entry/2020/10/10/121017

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The maker's answer to rough ceramic chips

Mr. Okada discussed surface coverings and restricted rough areas, while his reports left longer-term effects unresolved.

An unglazed ceramic thread hole prompted an initial coating requirement

In the June 2019 correspondence, the customer's concern began with the possibility of thread breakage. They wanted a ceramic chip with a hole but no embedded thread, and Mr. Okada said such a build was possible. His initial reply treated the resin coating as necessary even when the thread itself was absent.

The customer then asked about receiving the hole unfinished, and his later reply allowed that possibility. This was a change in what he offered to supply, without a recorded result from the customer's use. Mr. Okada's initial answer was that the exposed hole needed a covering, although his subsequent offer allowed an exception.

(Source: ok-lab's diary, published June 2019)
https://ok-lab.hatenablog.com/entry/2019/06/01/155432

Rough ceramic contact was limited to the enlarged sections

Mr. Okada's June 2019 custom response focused on which parts of the chip would remain against the sphincter. He wrote that the narrow sections could stay gripped, which concerned him if the chip rested at an unsuitable angle. The finish he supplied therefore reflected a concern about the location of contact, as well as the roughness itself.

His account describes a proposed way to reduce that contact, followed by an offer to hand over the custom item. It contains no report establishing how the finished version affected the recipient. Mr. Okada attached an own-risk qualification to that offer.

(Source: ok-lab's diary, published June 2019)
https://ok-lab.hatenablog.com/entry/2019/06/22/123034

Unglazed porcelain testing left prolonged contact with the sphincter unresolved

In October 2020, Mr. Okada reported that he noticed no bleeding during his porcelain test. His account differed from the sender's experience, which involved bleeding with an unglazed chip. These were separate people's reports, and the diary does not establish identical testing conditions.

Mr. Okada also stated that he had not tested prolonged use, leaving its effect on the sphincter unknown. His earlier June 2019 ceramic account had already identified excessive irritation at that structure. In that earlier entry, he warned that prolonged exposure to the rough ceramic surface was unsuitable.

(Source: ok-lab's diary, published June 2019)
https://ok-lab.hatenablog.com/entry/2019/06/15/144142

(Source: ok-lab's diary, published October 2020)
https://ok-lab.hatenablog.com/entry/2020/10/10/121017

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 rough ceramic chips changed over time

The diary does not say what the current state is.

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OK Prostate Chip products related to rough ceramic chips

The current list includes the ceramic model named in the June 2019 custom request.

Products that appear in these entries

(Source: ok-lab's diary, published June 2019)
https://ok-lab.hatenablog.com/entry/2019/06/22/123034

Products the diary mentioned as alternatives

The diary names no alternative.

The roughened ceramic test pieces and the threadless ceramic build were experimental or custom items discussed in June 2019. No matching product can be confirmed on the current list.

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Common worries about rough ceramic chips

The reader questions concerned unfinished holes, custom dimensions, and requests for stronger stimulation.

"Can an unglazed ceramic chip come without an embedded thread?"

In the June 2019 exchange, the customer wanted a hole instead of a permanently embedded thread because thread breakage worried them. Mr. Okada accepted the possibility of supplying that kind of ceramic chip. The customer's follow-up then shifted to the unfinished surface around the hole.

The correspondence records an agreement about possible manufacture, but no completed-order report or experience with that requested version. It also gives no result showing whether the customer's original concern about thread breakage was resolved. Mr. Okada initially specified a resin covering for the hole, before accepting the possibility of uncoated supply.

(Source: ok-lab's diary, published June 2019)
https://ok-lab.hatenablog.com/entry/2019/06/01/155432

"Can an unglazed ceramic chip be made in my size?"

In June 2019, the customer asked whether the hole or ceramic manufacturing process would limit a custom shape. Their proposed medium-length chip was 43 mm long. Mr. Okada replied that excessively thin shapes could have strength problems, but he thought the requested dimensions were workable.

At that time, only 9 existing ceramic shapes qualified for the usual production schedule. Custom work needed at least 5 weeks, and firing problems could add approximately 2 weeks. Mr. Okada therefore advised allowing a longer wait for a ceramic shape requiring custom manufacture.

(Source: ok-lab's diary, published June 2019)
https://ok-lab.hatenablog.com/entry/2019/06/01/155432

"Can rough ceramic chips provide stronger stimulation?"

In a separate inquiry published in June 2019, a customer wanted stronger stimulation after finding a previously purchased chip too narrow to feel much. Mr. Okada said he could not determine which option would suit that customer best. He included rough ceramic among the possibilities, while explicitly connecting that suggestion with his own injury.

The diary does not record which option the customer chose or how it felt afterward. His reply therefore contains a suggestion, without a successful customer result for the rough ceramic option. Elsewhere in the same entry, Mr. Okada warned against copying his rough ceramic experiments because of the injury risk.

(Source: ok-lab's diary, published June 2019)
https://ok-lab.hatenablog.com/entry/2019/06/15/144142

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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.