Privacy
Last updated 10 November 2026
Who is responsible
Tadahiro Koto, in Japan, is responsible for your personal information on this site. Use the contact form, or email support@seitai.tadahirokoto.com.
What we collect
- Your account: your email address, plan and membership status, and when you accepted the Terms and which version.
- Your viewing: which videos you've watched and where you stopped, so you can continue later.
- Your payment: from Stripe, your billing country, payment status and subscription details. We don't see or store your full card number.
- Technical information: your IP address, the country it suggests, and your browser type, in security and server logs.
- Your messages: your email address and anything you write when you use the contact form or email us.
- Visits to the site: which pages are opened, the site a visitor came from, and the country, browser and device type. We see these as totals, not as a record of what one person did.
- The launch list: your email address, if you ask to be told when we open.
Why we use it
| Purpose | Reason we're allowed to |
|---|---|
| Provide your membership and sign you in | To perform our contract with you |
| Check that we can sell to your country | Our legal obligations and legitimate interests |
| Keep the site secure and prevent account sharing | Our legitimate interests |
| Keep a record of what you accepted, in case of a dispute | Our legitimate interests |
| Understand how the site is used, so we can improve it | Our legitimate interests |
| Answer your questions | To perform our contract, or our legitimate interests |
| Tell you when we open | Your consent, which you can withdraw at any time |
Who we share it with
- Stripe and Link process your payments, receipts and billing support. They use your information under their own privacy policies.
- Vimeo plays the videos, so it receives technical information from your browser.
- Cloudflare hosts this site and its data, sends our emails and measures visits to the site.
We don't sell your personal information. We may also disclose it when the law requires us to.
International transfers
We're based in Japan, and our providers may process your information in other countries, including the United States. Where the law requires it, these transfers are covered by safeguards such as the standard contract terms that those providers offer.
How long we keep it
We keep account and viewing information while you're a member and for 12 months afterward. We keep a record of your email address and of when you accepted the Terms and which version for 6 years after your membership ends, so that we can show what was agreed if there's a dispute. We keep payment records for as long as tax and accounting law requires, which in Japan is usually 7 years. We keep messages you send us for 2 years. We delete launch list emails when you unsubscribe, or after the launch if you don't join.
Cookies and analytics
We use one essential cookie to keep you signed in. We don't use advertising cookies, and we don't follow you across other sites.
To count visits, we use Cloudflare Web Analytics. It doesn't use cookies, doesn't store anything in your browser and doesn't build a profile of you.
The Vimeo video player may set its own cookies when you play a video. Stripe sets cookies on its checkout and billing pages to prevent fraud.
Your rights
Depending on where you live, you can ask to see, correct, delete or receive a copy of your information, or object to how we use it. To make a request, use the contact form or email us, and we'll answer within one month. If you're in the EU or UK, you can also complain to your data protection authority.
Children
This site is for people aged 18 or over, and we don't knowingly collect children's information.
Changes
If we make an important change to this policy, we'll update this page and email members.