Privacy Policy

Version: 2026-10-28

Added 2026-10-29: the item “Records of suggested videos” and a few other lines. This concerns only members who send a video suggestion, and you do not need to agree again.

This policy explains what information the whole of flatwaterpopup.com (the "Site") handles and how. We keep almost nothing about people who only watch videos.

Operator

Operator: Akihiro Iwaya
Contact: please write to us through the Contact link at the bottom of this page. Email us
We do not publish a postal address or phone number here. We will give them without delay if you ask.

Information we keep about members

From members we keep only the information below. For each item we say what it is used for, who can see it, and when it is deleted.

Google account number

What it is: A number Google assigns to each person. It is not a name.
Required?: Required
Who can see it: Nobody (it stays inside the server)
Used for: Recognizing you as the same person the next time you log in
Deleted when: You leave; the operator deletes it at your request, or removes you for breaking the terms; or the registration is left unfinished (removed in the first morning clean-up after 24 hours have passed, so it can stay for up to almost 2 days)

Email address (from Google)

What it is: The email address Google gives us (saved in lower case). We also record a mark that Google has checked the address (we accept only "yes", so it is always "checked")
Required?: Required
Who can see it: You (on the My account page) and the operator (in the database) only. It is not shown to other members or to the public. Even the data the screens use (the API) returns it only to you, for your own My account page. When handling requests such as deletion, the address may be passed to an AI that helps the operator (see "Contact emails")
Used for: Checking who you are when you ask for deletion, and for important notices such as changes to the terms
Deleted when: Same as above

Nickname

What it is: To check that it does not clash with another member's, we also record a version with upper/lower case, full-width/half-width forms and look-alike letters of other alphabets (such as Cyrillic "а" and Latin "a") made the same (it changes and is deleted together with the nickname)
Required?: Required
Who can see it: You and the operator. When you put out a practice spot, logged-in members see it together with the spot. When you press "I'd like to practice with you", the person who put out that spot sees it. A member you are connected with sees it too (not in these ways between members where one has chosen not to see the other; but a member who chose not to see you still sees your present nickname in their own list of such members). When handling a report about a member who breaks the terms, it may be passed to the AI that helps the operator (see "Contact emails")
Used for: Showing who wrote a spot, who pressed, and who you are connected with
Deleted when: Same as above. When you change it, the old one is not kept

Country (code)

Required?

Required

Who can see it

You and the operator. Anyone can also see the number of members per country and per state on the member map (Find riding buddies), including a country or state with only one member. The counts are never linked to nicknames.

The counts alone do not show who anyone is. But combined with what someone already knows (for example, that a certain person rides in that area), they could suggest whether that person is a member, and more easily in an area with few members. A logged-in member who compares the list of practice spots (with nicknames) with the day-to-day changes of the map may also guess the state where a member lives.

A member who has agreed only to a version earlier than 2026-10-28 is counted without a country or state (only in the total and in “Members not shown by place”) until they take a step to agree to the new version (“Agree to the new version” on My account, or ticking the box for the new version for practice spots and the like). Just continuing to use the Site does not put your country or state on the map. At present, the only way not to be counted on the map is to leave. Counts are updated once a day, so a change or leaving shows on the map at the next update (7:00 Japan time, 22:00 UTC).

Separately, the country and state of a practice spot are chosen for each spot and are not your own place. Logged-in members can see which countries and states have practice spots and how many (apart from the member map's counts; it shows only about members who put out a spot)

Used for

The member map; the country and state filled in at first when you put out a practice spot

Deleted when

Same as above. When you change it, the old one is not kept

State or prefecture (code)

Required?: Required (not needed for countries without a list of states)
Who can see it: Same as country (the state of a practice spot is also chosen for each spot and is visible to logged-in members)
Used for: Same as country
Deleted when: Same as above

Confirmation that you are 18 or older (the date and time you answered yes)

Required?: Required
Who can see it: You and the operator
Used for: A record of the promise that members are 18 or older
Deleted when: You leave; the operator deletes it

Version and time of the Terms of Use and Privacy Policy you agreed to

Required?: Required
Who can see it: You and the operator
Used for: A record of what you agreed to; and whether the member map counts you by country and state (only members who agreed to the version of 2026-10-28 or later)
Deleted when: Same as above

When you registered and last changed your details

Required?: Automatic
Who can see it: You and the operator
Used for: A record of registration
Deleted when: Same as above

Practice spots (country and state, name of the place, note, number, the member who wrote it, the time it was put out and last changed or "still practicing" was pressed)

Required?: Optional (up to 3 per member)
Who can see it: Logged-in members who have finished sign-up (with the nickname of the writer; not if either has chosen not to see the other), you, and the operator
Used for: Telling others about your usual practice spots
Deleted when: You delete it; you change it (the old content is not kept); 90 days after it was last put out, changed or kept with "still practicing" (each spot on its own, in the morning clean-up); you leave; or the operator deletes it

Contacts (LINE ID, Instagram name, email address; one of each at most; only in the set forms)

Required?: Optional (at least one to press "I'd like to practice with you" or to say OK)
Who can see it: You, the operator, and only the people you are connected with (people you said OK to, and people who said OK after you pressed "I'd like to practice with you": when you press, your registered contacts are shown to that person once they say OK). Not in the lists of spots or in notices
Used for: Showing to the people you are connected with
Deleted when: You delete or change it (the old one is not kept); you leave; or the operator deletes it

"I'd like to practice with you" (who pressed, which spot, when)

Required?: Only when you press it (up to 10 at a time)
Who can see it: The person who pressed, the person who put out the spot, and the operator. Nobody else. Whether the person who put out the spot has seen the notice is not shown to the person who pressed
Used for: Telling the person who put out the spot, and getting their OK
Deleted when: OK is said (it becomes a connection); the person who pressed takes it back; 30 days after it was pressed (morning clean-up); the spot is deleted; one chooses not to see the other; or either leaves

Connections (the two who said OK, who pressed, the time of OK)

Required?: Automatic
Who can see it: The two people and the operator
Used for: Deciding whom to show each other's contacts to; the OK notice to the person who pressed (30 days)
Deleted when: Either ends it; either chooses not to see the other; or either leaves

Record of "do not see" (who chose, whom, when)

Required?: Optional
Who can see it: The member who chose and the operator. The other person is not told
Used for: Not showing each other
Deleted when: The member undoes it; or either leaves

When you last looked at your notices

Required?: Automatic (when you open the notices and connections screen)
Who can see it: You and the operator
Used for: The number on the "Notices 1" mark
Deleted when: You leave

When you agreed to the practice-spot rules

Required?: When you first put out a spot, press "I'd like to practice with you", or say OK
Who can see it: You and the operator
Used for: A record that you agreed to the safety notes and the terms (so that you are not asked again)
Deleted when: You leave

Records of suggested videos

What it is

The member who sent it, the number of the video, and the date and time it was sent. Recorded when a member sends a video address (up to 5 a day). The text that was pasted is not stored: only the video number is taken out of it and the link is built again

Required?

Only when you send one (up to 5 a day)

Who can see it

The operator only. It is not shown on the Site or on your own screen (ask us through the Contact link if you want to know). The morning email that reaches the operator shows only the title and channel of a video and how many people suggested it, and does not say who sent it.

To deal with pranks, the AI that helps the operator (see "Contact emails") may see how many members sent a given video and the list of videos each of those members sent in the last 30 days (their nicknames and email addresses are not shown to it).

Used for

Counting up to 5 a day; telling the operator how many members suggested a video; and, when pranks go on, checking whether they come from the same member so that the member can be removed

Deleted when

In the first morning after 30 days have passed since it was sent (so it can stay for up to almost 31 days); you leave; or the operator removes you. The video number and address, and the title and channel taken from YouTube, stay in a form that does not show who sent them (so that the same video is not announced again and again)

Login record

What it is: A cookie with a secret key in your browser, and a record with an expiry on the server
Required?: Only while you are logged in
Who can see it: Your browser and the server only (the cookie cannot be read by scripts in the browser)
Used for: Keeping you logged in
Deleted when: You log out; it expires 30 days after last use (cleared every morning); or you leave

Temporary records during registration and login

What it is: A check value that stops others from hijacking the exchange with Google, and the mark of your consent before registration. It is put in a browser cookie for 10 minutes, only when you press "Log in with Google" or "Sign up with Google" (scripts in the browser cannot read it, its contents are encrypted, and changing it makes it invalid). It is not stored on the server
Required?: Automatic
Who can see it: Your browser and the server
Used for: Preventing interruption, and remembering your consent until you return from Google
Deleted when: You return from Google, or it expires after 10 minutes

Information we do not keep

Real name (Google name, given name, family name), profile photo, and Google language or region settings: we do not ask Google for them and do not store them if they arrive
Google access keys (access token, refresh token, ID token): thrown away after they are used to check the login
Date of birth or age (we record only a yes to "Are you 18 or older?")
Address, phone number, payment details, precise location (GPS, map points), or your city, town or village (your area is kept only down to country and state or prefecture)
Messages: there is no way to send a message inside the Site
A precise position of a practice spot (map point, GPS), photos, gender or age
Records of looking: apart from when you last looked at your notices, we do not record who looked at what
The text pasted for a suggestion: only the video number is taken out of it and the link is built again; what was pasted (values such as "?si=…", and any text around it) is not stored
A message attached to a suggestion: there is no box for one
IP address, browser or device type: not stored (used only briefly to limit the rate of requests)
Linking favorites to members: favorites stay under a random number per browser and are not linked to a member number
Tracking members with analytics

Information about people under 18

Members of this Site must be 18 or older. We do not keep information about people under 18.

Contact emails

Emails sent through the Contact link are forwarded to the operator's Gmail (Google) and used to reply and to handle requests such as deletion. A record of the forwarding stays at Cloudflare for a period of time. When handling requests such as deletion, the email address of the person who wrote may be passed to an AI that helps the operator with the work (Claude, by Anthropic, in the United States). When handling a report of a post or a member that breaks the terms, the number of the practice spot to delete and the nickname of the member to remove may be passed to the same AI. The AI then sees only the number and nickname it is given and the result of the command (such as how many things were deleted, or that nothing was found, that the nickname did not match the number, or that it could not decide which member): the name of a place, a note, contacts, email addresses and regions are not passed on. Emails are deleted within one year after the matter is handled.

Favorites

Your favorite videos are saved in your browser. To count favorites, your browser also sends the server a random number it makes by itself (one per browser, not a name) together with the list of videos you marked. It is not linked to a member number or nickname. When you remove a favorite, it is removed from the server's record too. If you clear your browser's data, the record left on the server stays, but nobody can tell whose it is (it is kept to count favorites).

Temporary use and error logs

To stop too many requests being sent, the IP address is used briefly. It is not stored. Server error logs do not contain personal information and are deleted after 30 days.

Outside services

This Site uses the outside services below. When you open a page, your IP address and similar information reach these services.

Cloudflare: delivering the Site, the database, analytics, and email forwarding
Google: login, and Google Fonts (typefaces)
YouTube: embedded videos and thumbnail images. To check that a YouTube video suggested by a member exists and is public, we ask YouTube's official interface (the YouTube Data API) with the video number only (we do not tell it who suggested it)
Instagram: embedded posts, and a link to the Instagram page of a member you are connected with (nothing reaches Instagram from this Site until you press it). Facebook: a link only (pressing it takes you to Facebook)

This Site does not send email to the contacts, and does not ask LINE or Instagram anything.

How each service handles information follows its own terms and policy.

What you can do

Members can see, correct and delete (by leaving) their information on the My account page. Records of suggested videos are not shown on My account; if you want to know them, write to us through the Contact link and we will answer by email. On the My practice spots and contacts screen and the Notices and connections screen, you can change or delete spots, change or delete contacts, take back a request, end a connection, and choose not to see someone or undo it. If you cannot leave yourself, or have any other question, please write to us through the Contact link at the bottom of this page. We act only on requests that come from the registered email address, respond within one month, and reply to you.

When you leave, the information you gave (including records of suggested videos, practice spots, contacts, requests, connections and the records of "do not see") is deleted immediately. However, the backup that lets the database be restored to an earlier point in time can keep deleted information for up to 30 days.

Changes to this policy

This policy may be changed when needed. When it changes, the new version (date) is shown on this page. A small change that does not need you to agree again may be made without a new version; it is then shown as a dated addition under the version line.

Japanese and English

This policy is also available in Japanese. If the Japanese and English versions differ, the Japanese version prevails.