Nagi Privacy Policy
Version 1.1 · August 31, 2026
Nagi (the "App") is provided by TRUTH Corporation (トゥルース株式会社)("we", "us"). This policy explains what information the App handles, which of it stays on your phone, which of it reaches our servers, how we use and protect it, and what rights you have. The Japanese and English versions say the same things under the same numbers.
Nagi records the sound of your night and tells you in the morning what it heard. It does not diagnose. It never claims to have found a condition.
1. Who we are (the controller)
- Name: TRUTH Corporation (トゥルース株式会社)
- Address: 4-13-5-303 Minamigyotoku, Ichikawa, Chiba 272-0138, Japan (the registered head office)
- Contact: support@mynagi.jp
- Scope: the Nagi apps for iOS and Android and the small cloud record behind them (section 3)
2. What stays on your phone (and never reaches us)
When you start a night, the App listens through your phone's microphone and software on the phone analyses the sound as it happens. None of the following leaves the phone. It is never sent to our servers, we never see it, and we cannot reconstruct it.
- The audio of the night. The sound is sent nowhere. Only the loud stretches are kept. Those delete themselves after fourteen nights; you can delete them earlier from within the App at any time.
- The loudness shape of the night in five-second steps, the time of the loudest moment, the moments you marked as "not me", and any stretch where recording stopped and why.
- A diagnostic log that records only when recording started, ended, was interrupted and resumed (no audio, no numbers; it leaves the phone only if you share it yourself from Settings).
- Your reminder time, region, sensitivity and whose-night settings.
- Health readings (if you connect Apple Health or Health Connect): sleep, heart rate and respiratory rate are read and shown on the phone only, never written back and never transmitted.
3. What your account holds (what reaches our servers)
When you first open the App, an anonymous account with no name and no email is created automatically. If you later sign in with an email address, Google or Apple, the account stays the same and your record becomes readable on a new phone.
Only the items below reach our servers. For each we state the purpose, the legal basis, the retention and how to delete it.
| Item | What it is | Purpose | Legal basis | Retention and deletion |
|---|---|---|---|---|
| Account identifier | The identifier created automatically at first launch | Providing the account | Contract | Until you delete the account |
| Email address | Only when you sign in with email, Google or Apple | Sign-in and restore | Contract | Until you delete the account |
| Display name | The name Google or Apple passes to us (only when used) | Sign-in | Contract | Until you delete the account |
| A per-night summary | Date, minutes of loud sound (your share), peak time, recorded length, your morning feel (one of three), your answer to the first question, tag ids, whose night | Restoring your record after a new phone or a reinstall | Your explicit consent (section 5) | Until you delete the account |
| Your own tag words | The names of tags you add yourself, with created and deleted times | So a restored record shows your tags as words | Your explicit consent (section 5) | Until you delete the account |
| Usage events | Twenty named events (for example "night started", "morning read seen") and five properties: plan, first answer, language, OS, health app connected. Never a night's numbers or sound | Improving the App | Legitimate interest (off in the EEA, UK and Switzerland until consent exists) | Aggregated, at most 14 months |
| App identifier | An identifier assigned to each installation for analytics and crash reports (not an advertising identifier) | As above | As above | As above |
| Approximate location | The country or region the analytics service derives from a masked IP address (never a precise location) | As above | As above | As above |
| Crash reports | Stack trace, device and OS information when the App crashes | Fixing defects | Legitimate interest | 90 days |
| Purchases and plan state | Purchase history through the store and whether the plan is active (card details never reach us) | Providing and restoring the paid plan | Contract | Until you delete the account |
Nothing outside this table reaches us. The sound is sent nowhere. Only the loud stretches are kept. The night's shape, marks, health readings, the diagnostic log and the region setting never leave the phone either. We do not read advertising identifiers and we do not track you.
4. The microphone, and the other person in the room
The App's microphone runs all night in a bedroom, so it may pick up sound that is not yours: a partner's breathing, snoring or sleep talk.
Whose sound it is makes no difference to how it is handled. The sound is sent nowhere. Only the loud stretches are kept. All of it is analysed on the phone, and we neither receive nor see it. The App does not try to identify who is speaking or snoring. The clips can be played and deleted only on the phone. In the morning you can mark a moment as "not me" and it leaves the number; a mark changes the number and never deletes the recording.
Because this audio never reaches us in any form, our position is that we do not "handle" it under Japan's Act on the Protection of Personal Information. That is our reasoned reading, not a settled ruling; no regulator has published guidance on an app built this way, and we would rather say so plainly than overstate it.
If you share a bedroom, please make sure the person beside you is comfortable with a microphone recording the room, and that doing so is appropriate under the law that applies to you.
5. How we use the information, and the legal bases
We use the information in section 3 only to:
- create and keep your account, and restore your record after a new phone or a reinstall;
- show your nights against your own usual (the comparison itself is computed on the phone);
- provide and restore the paid plan through the App Store or Google Play;
- run the App safely, fix defects and understand what is used;
- comply with the law and enforce the Terms.
Explicit consent. The per-night summary and your own tag words concern your health. We obtain what GDPR Article 9(2)(a) calls explicit consent (EEA and UK) and what Japan's Act on the Protection of Personal Information Article 20(2) calls prior consent for sensitive personal information, through your own action at these points:
- the screen where you create an account or sign in (one sentence before "Continue" states what is saved); before that consent, no summary leaves the phone;
- the screen where you connect a health app (during setup or later); the reading stays on the phone and the values are not transmitted.
You can withdraw consent at any time: deleting the account removes the summaries; disconnecting a health app stops the reading.
Other bases. The account and purchases: performance of our contract with you. Crash reports and usage events: our legitimate interest in keeping the App safe and improving it (in the EEA, UK and Switzerland, usage events are off by default). Legal obligations where they apply.
6. Recipients, and transfers abroad
We do not sell your information. We do not use it for advertising. We do not join it with other companies' data.
Only processors acting on our behalf, under contract and to the extent needed, touch the information.
| Processor | Role | Information touched |
|---|---|---|
| Google (Firebase) | Authentication, storage of the per-night summary and tags, aggregation of usage events, crash reports | The relevant rows of the table in section 3 |
| RevenueCat | Managing the paid plan's entitlement | Purchase history, plan state, account identifier |
| Apple, Google | Purchases and payment through the App Store and Google Play | Under each store's own terms |
Their servers are mainly in the United States. For transfers from the EEA and UK we rely on appropriate safeguards such as Standard Contractual Clauses. For transfers from Japan we follow Article 28 of the Act on the Protection of Personal Information: this policy gives the reference information for the provision to a third party abroad and we obtain your consent.
If disclosure is required by law, needed to protect our or others' rights and safety, or follows a transfer of the business, we will tell you in advance where the law allows.
7. Retention
Account information and per-night summaries are kept while the account is active and deleted within a commercially reasonable period after a deletion request (except where the law requires retention). Usage events are kept as aggregated data for at most 14 months; crash reports for 90 days.
What is on the phone (audio, the night's shape and so on) stays when the account is deleted. Delete it from the App's Settings, or by removing the App.
Your own record (the morning numbers, the playback, the history) is free forever, whether or not you subscribe.
8. Your rights, and how to use them
Depending on where you live, you have the right to access, correct, delete, export and restrict the processing of your information, to object, and to withdraw consent. This includes the EEA and UK (GDPR), Japan (the Act on the Protection of Personal Information) and California (CCPA/CPRA), among others.
- Delete: Settings > Account > Delete account. Every summary and tag under your account is deleted. Works only while online.
- Delete audio on the phone: Settings > Recording, or from any night's own page.
- Revoke the microphone permission: at any time in the phone's settings; the App cannot record without it.
- Access, export, correction: contact us at the address in section 1. The summaries are readable in the App as they are.
- Complaints: to the Personal Information Protection Commission (Japan) or, in the EEA and UK, to the supervisory authority of your country.
We will not treat you differently for exercising a right.
9. Children
The App is not directed to anyone under 16. We do not knowingly collect personal information from anyone under 16. If you believe we have, contact us at the address in section 1 and we will delete it.
10. Changes
When this policy changes we update the version and date and, for material changes, tell you inside the App. Where a change needs consent, we ask for it again.
11. Contact
TRUTH Corporation (トゥルース株式会社) 4-13-5-303 Minamigyotoku, Ichikawa, Chiba 272-0138, Japan support@mynagi.jp
This policy is governed by the laws of Japan.