Privacy Policy

1. Who we are

Jukuna is an adaptive AI exam-preparation platform operated by Jukuna Education K.K.(“Jukuna”, “we”, “us”), the personal-information handling business responsible for your data under Japan’s Act on the Protection of Personal Information (APPI). Contact us at hello@jukuna.com.

2. What we collect

• Account information. Your email address, display name, and Google OAuth profile when you sign up.
• Year of birth. We ask students for their birth year only (not a full date of birth) to apply the legally-required age and guardian-consent rules. See section 8.
• Practice data. Questions answered, scores, subjects, topics, difficulty ratings, and timestamps — used to power your adaptive ELO and score predictions.
• Usage data. Pages visited, features used, and session length — collected in aggregate to improve the product.
• Class data. If your teacher adds you to a class, we store your class membership and any assignments your teacher creates.

3. How we use your data & purpose of use

In line with APPI’s purpose-specification requirement, we use personal data only for the following purposes:

• Provide and improve the adaptive learning service.
• Generate personalised study plans and score predictions.
• Allow teachers to view their students' progress and assign practice.
• Verify a student's age and route guardian consent where required by law.
• Send transactional emails (account-related only — no marketing without consent).
• Detect and prevent abuse.

We do not sell your personal data, and we never use student data for behavioural advertising.

4. Sub-processors & where your data is processed

We use the following sub-processors to deliver the service:

• Supabase. Database, authentication, and file-storage hosting. Your account and practice data are stored in the Seoul, South Korea region (AWS ap-northeast-2).
• Google (Gemini API). AI question generation and answer evaluation. Practice content and prompts are sent to Google's Gemini API (processed in the United States / Google global infrastructure).
• Resend. Transactional email delivery (e.g. parent-consent and account emails).
• Cloudflare. Bot-protection (Turnstile) on our sign-up and contact forms.
• Vercel. Application hosting and edge delivery.

We do not sell your personal data to any third party.

5. International data transfers

Jukuna is operated from Japan, but to deliver the service your personal data is transferred to and processed by our sub-processors outside Japan — principally in South Korea (database & storage hosting) and the United States(AI processing, email, bot-protection, and application hosting). We rely on these providers’ contractual and security commitments to protect your data to a standard equivalent to that required under APPI. By using Jukuna you are informed of, and consent to, these cross-border transfers.

6. Data retention

We retain your account and practice data for as long as your account is active. If you delete your account, your personal data is deleted within 30 days. Anonymised aggregate statistics may be retained indefinitely.

7. Your rights

Under APPI (and, where applicable, COPPA and FERPA) you may request to access, correct, export, suspend the use of, or delete your personal data.

• Self-serve. You can download a copy of your data or delete your account at any time from Settings → Your data and Settings → Danger zone.
• By request. Email hello@jukuna.com and we will respond within 30 days.
• Complaints. If you are in Japan, you may also contact the Personal Information Protection Commission (PPC).

8. Children & students (APPI, COPPA & FERPA)

Draft pending legal review. This section describes our intended practices for student users and should be reviewed by counsel before launch.

We ask every student for their birth year and apply a guardian-consent gate to minors. Under APPI, a student under 16 needs a parent or guardian’s approval; under the US COPPA rule the threshold is 13. We apply the stricter under-16 gate by default.

• Self-signup minors. A student under 16 who signs up on their own is blocked from practising until a parent or guardian approves their account through a secure, email-verified link. We record the consent and the timestamp.
• School-provisioned minors. Where a school, district, or teacher enrolls students, the school may attest that it has obtained any guardian consent required, under the COPPA school-consent exception, with Jukuna acting as a “school official” with a legitimate educational interest under FERPA. Student records are handled per our Data Processing Agreement.
• Parental rights. Parents can review their child's activity and request access or deletion through the linked-parent flow or by emailing us.
• No direct marketing to children. We send students only account-related, transactional messages — never marketing.

If you believe a child has provided us personal data without appropriate school or guardian consent, contact hello@jukuna.com and we will delete it. See also our Data Processing Agreement.

9. Cookies

We use essential cookies only — session tokens required for authentication. We do not use advertising or tracking cookies.

10. Changes

Material changes will be notified by email or a prominent in-app notice at least 14 days before they take effect.

11. Contact

Questions? hello@jukuna.com