Privacy Policy
Last updated: 2026-10-07
The operator of Janken Kingdom (the "App"), Ikeda Tomohiro (the "Operator"), handles the information of users of the App as described below.
1. Information we collect and why
| Information | Details | Purpose | Stored in |
|---|---|---|---|
| Nickname | The name you choose (at first, the server assigns one like "Adventurer ####"). It can be changed once every 30 days. | Shown to opponents, friends, and in rankings | Server |
| Account ID and secret | Random values the server issues for each account | To tell accounts apart and accept actions only from the account owner | Server and your device |
| Friend information | Friend ID (an 8-character code shown to players), friend relationships, request records, recent opponents (30 days are shown; up to the latest 50 per person are kept), and friends whose room invitations you muted | Friends, the recent-opponents list, and invitation controls | Server |
| Match records (Replays) | For Rank Matches and Room Matches: the cards played, the result, both players' nicknames, and characters. Up to the latest 100 matches per type for each player | Watching replays and reviewing matches | Server |
| Points and stats | Points, numbers of wins, losses, and draws, the dates and counts used for win bonuses, monthly wins and losses, the number of seasons played, and the times of matches against the same opponent | Rankings, titles, matchmaking, and limits on repeated matches against the same opponent | Server |
| Ranking history | Final rankings of past seasons (rank and points) and the top 100 of past months (rank, wins, and losses) | Showing past rankings | Server |
| Notification token | The device token for Android notifications (Firebase Cloud Messaging). Up to the latest 5 per account | Notifications, for example when you are invited to a room | Server, and Google (Firebase) |
| Transfer code | A code you generate to transfer your account. The code itself is not stored; only a hash is kept, for 24 hours after it is issued | Moving to a new device or reinstalling | Server |
| Connection information | The IP address of the connection and similar data used in communication | Handling communication and preventing abuse (such as repeatedly guessing transfer codes) | Failed attempts are counted in server memory only (not stored). Other handling: see section 6. The web server in front of the game server (Caddy) does not store access logs (IP addresses, etc.). |
| Operation logs | Records of match progress and errors. They may include nicknames and match content | Investigating problems and operating the server | Server (retention: see section 6) |
The following is stored only on your device and is never sent to the server: Story Mode progress, the character gallery records, settings such as volume, and whether you have seen the tutorial.
Room chat and invitations are handled only in server memory and are not stored (they disappear when the server restarts).
The App does not collect location, contacts, photos, microphone input, advertising IDs, or payment information. It also does not use any advertising or usage-analytics mechanisms.
2. Information visible to other players
The following information is visible to other players.
- Nickname, title, points, rank, and monthly wins and losses (on the ranking screen). However, players whose monthly "wins minus losses" is negative are not shown to others (only to themselves).
- Your nickname and chosen character during matches and in rooms.
- Your nickname, to friends and to people you invite or who invite you to a room.
- A match replay can be viewed by the two players who took part in that match.
Please do not use your real name or any information that could identify you in your nickname.
3. Sharing and service providers
Except where required by law, the Operator does not provide users' information to third parties without consent. However, the following services are used to provide the App.
- Google LLC: (1) Notification delivery (Firebase Cloud Messaging). Your device token and the notification content (for a room invitation, the room name and the inviter's nickname) are passed to Google. (2) Server hosting (Google Cloud).
- DuckDNS: provides the server's domain name.
- Cloudflare, Inc.: delivery of this website (Cloudflare Pages). When you view the website, access information (IP address, date and time and pages viewed, browser type, etc.) is processed and recorded by Cloudflare for delivery and security. The website does not use cookies. Information from the game App (nickname, match records, etc.) is not passed to Cloudflare.
4. Storage outside Japan
The game server is located in the United States (Google Cloud region us-west1). Your information is stored on a server outside Japan. The website is delivered from Cloudflare's locations around the world.
5. Security measures
Communication between the App and the server is encrypted (HTTPS/WSS). Server data is managed so that only the Operator can access it.
6. Retention, and what remains after you delete your account
- When you delete your account, all of the following is removed from the server. This cannot be undone. Your nickname, account ID and secret, friends and their requests, recent opponents, invitation-mute settings, points and stats, notification tokens, unused transfer codes, and the replays of matches you took part in (they also disappear from your opponents' lists).
- What remains after deletion: rows in the final rankings of past seasons and the top-100 lists of past months are kept in a form that is not linked to any individual. Only the season (month), rank, points, and title (or wins and losses) remain; the account ID, nickname, and anything else that could be linked to you are deleted. The entry is shown as "Deleted user". Ranks are not closed up, so other players' ranks and the number of entries do not change. A hash of the ID is not kept either, because it could be matched if the original ID were known.
- Operation logs (section 1) may remain after deletion until their retention period ends. The retention period is up to 30 days.
- Even if you do not delete your account, replays beyond the latest 100 matches per type are removed. Recent opponents older than 30 days are not shown, and entries beyond the latest 50 per person are removed. A transfer code becomes invalid 24 hours after it is issued, and its hash is deleted.
- Uninstalling the App from your device does not delete your account information on the server. To delete it, please use one of the methods in section 7.
7. How to review and delete your information
- In the App: Settings → Account → Delete account. You are asked to confirm twice.
- If you cannot use the App: please contact us by email as described in Delete Your Account & Data. We may ask for additional information to confirm that you are the account owner.
- When changing devices or reinstalling, you can move your account to the new device without deleting it by using a transfer code under Settings → Transfer. Do not share the code with anyone. Once you enter it on the new device, the account can no longer be used on the original device.
8. Use by children
This App is intended for people aged 13 and over. People under 13 may not use it. If you are under 18, please use it with the consent of a parent or guardian. Your nickname and room chat are visible to other users, so please be careful. If we learn that we have collected information from a child under 13, we will delete it promptly.
9. Changes to this policy
When this policy changes, this page will be revised and the last-updated date will be updated. Significant changes will be announced in the App or elsewhere.
10. Contact
Operator: Ikeda Tomohiro
Contact: dev.iketomo@gmail.com