Notice under the Act on Specified Commercial Transactions, privacy policy, terms of use
Soroban Kingdom is a soroban practice app built and run by an individual. Money, the data we handle, and the rules are all written here.
▼ Notice under the Act on Specified Commercial Transactions ▼ Privacy policy ▼ Terms of use ▼ Contact
Notice under the Act on Specified Commercial Transactions
Soroban Kingdom is run by an individual. For the peace of mind of children and families, we keep what we collect to a minimum, and run no advertising (we only use Cloudflare Web Analytics to count visits — no cookies). Data is stored encrypted on Google Firebase (Tokyo).
| Seller | Soroban Kingdom Operations Office |
|---|---|
| Representative | Tomoko Sutou (須藤智子) |
| Address | Disclosed without delay on request (please write to the email address below) |
| Phone number | Disclosed without delay on request (enquiries are taken by email) |
| Email address | [email protected] |
| Price | Prices in US dollars (shown on each page):
|
| Costs other than the price | The data charges for your internet connection. For the US dollar plans, sales tax or VAT may be added at checkout, depending on your country. |
| Payment method | Credit card (processed by Stripe). The US dollar plans are sold through Stripe Managed Payments: Stripe (shown as “Link” on the checkout page and receipt) is the merchant of record and handles payment and taxes. Soroban Kingdom provides the service and support. |
| When payment is taken | The first payment is taken on the day you subscribe. After that, payment is taken automatically on the same date every month (every year for yearly plans). |
| Free trial | Families and schools can try it free for 14 days. No credit card is needed, and you are never charged automatically: the trial simply stops after 14 days. To continue, subscribe to a plan (billing starts that day). Levels 20–16 are free forever with no sign-up. |
| When the service is provided | Immediately after you subscribe. The plan is applied automatically within minutes (within 1 business day at the latest). |
| Cancellation | Any time, from the customer page (customer portal: https://billing.stripe.com/p/login/14A8wO89AcNJ0lPfYMe7m00). The plan stops at the next renewal date, and you can keep using it until then. No pro-rated refunds. |
| Returns and cancellation | As a digital service there are no returns. If a fault on our side made it unusable for a period, we refund that period |
| Supported devices | The latest Chrome, Safari or Edge. Phone, tablet or computer |
| Contact | See "Contact" below (email: [email protected]) |
Privacy policy
What we collect
- Teacher (school): if you sign in with Google, the Google account's email address and display name, and your name (or school name). If you register by email, the email address, your name (or school name) and a password (encrypted; even the operator cannot see it)
- Students: only the nickname and practice records (date, level, subject, right or wrong, time, how the mistake was made)
- Parents (family trial, Home Plan, and families joining a class): the email address and display name of the Google account used to sign in
- Families (Home Plan): email address and payment details (credit card numbers are handled by Stripe and never held by this site)
What we do not collect
We do not collect students' real names, dates of birth, addresses, photographs or location. We never ask a student for an email address.
About parents signing in
For the family trial, the Home Plan, and families joining a class, a parent signs in with a Google account (email address and display name). It is used only to check the plan and to link the child with the device; we never send you advertising email and never pass it to anyone else. If you use only levels 20–16 (free forever), no sign-in is needed.
What appears in the ranking
A child appears in the public ranking only after a parent turns it on. This is done on the parent screen, signed in with the parent's Google account: the screen shows exactly what will be published, and the parent ticks "I am this child's parent or guardian, and I agree to the information above being made public" before pressing "Show in the ranking". Children cannot turn it on by themselves. The ranking shows the nickname, country, class name (if entered) and the number of correct answers this month; anyone can see it. We never collect real names. A parent can press "Stop showing" at any time on the same screen, which removes the child from the ranking. We also keep the date of the parent's consent. Please make sure the nickname does not contain the child's real name or school.
What the video contest collects
Only from parents who enter the video contest: the email address of the Google account used to enter, a family nickname, country, the social network used, the video link and the number of children taking part. Bank details are asked only of the grand-prize winner and deleted after payment. We do not collect postal addresses.
What it is used for
Showing practice records, sharing them with the teacher, homework, payment processing, and replying to enquiries. Nothing else.
Do we share it with anyone else?
No, we do not (except where the law requires it). Companies we entrust processing to: Google (Firebase), Stripe (payments) and Cloudflare (serving the site and counting visits). We run no advertising. Visits are counted with Cloudflare Web Analytics, which uses no cookies and does not track individuals; it only totals the pages viewed, where visitors came from, country and device type.
Children under 13 (COPPA)
Soroban Kingdom is used by children. We do not collect personal information from children under 13 without a parent's consent.
- At home, a parent signs in with their own Google account, confirms that they are the child's parent or guardian and 18 or older, and registers the child's nickname.
- In a school, the teacher registers the students. Schools should register students only with their parents' consent.
- There is no screen that asks a child for their real name, email address, date of birth, address or photo.
- A parent decides, on the parent screen, whether the child's nickname appears in the ranking.
Parents' rights
At any time, a parent can see, correct or delete their child's records, or stop us collecting more. The parent screen has a "delete all records" button; you can also email [email protected]. After confirming who you are, we respond within 30 days. When a teacher deletes a class or a student, those records are deleted too.
Where data is stored, and transfers abroad (GDPR / UK GDPR)
Data is stored in Google Firebase (Tokyo region, Japan) and on your own device (settings and records). Japan is recognised by the European Union and the United Kingdom as providing an adequate level of protection for personal data (EU adequacy decision of 2019, carried over by the UK).
Legal basis (GDPR)
We store and show practice records to provide the service under our agreement with the parent (or the school). Showing a nickname in the ranking is based on the parent's consent, which can be withdrawn at any time. If you live in the EU or the UK, you also have the right to complain to your local data protection authority.
How long we keep records
Records are deleted one year after a plan ends. When a teacher deletes a class or a student, or a parent presses "delete all records", the records are deleted immediately.
Questions and deletion requests
Account deletion and any question: [email protected].
Changes
If anything changes, we will say so on this page. Effective 12 September 2026. Revised 9 October 2026: the ranking section now describes that a parent, not the child, decides whether the child appears (the app itself changed on 6 October 2026); added the sections on children under 13, parents' rights, storage and transfers abroad, legal basis and retention. Revised 11 October 2026: added that visits are counted with Cloudflare Web Analytics (no cookies).
Terms of use
- Service: Soroban Kingdom (sorobankingdom.com) provides a soroban practice app and a teacher screen for schools.
- account: the teacher screen is used by signing in with a Google account, or created with an email address and a password. For the family trial, the Home Plan and families joining a class, a parent signs in with a Google account. Please look after your account and password yourself.
- What you must not do: using someone else's account, tampering, causing trouble for other users, and reposting or redistributing the material.
- Fees and cancellation: Prices are as shown on each page. Levels 20–16 are free forever with no sign-up. Families and schools can try a plan free for 14 days with no credit card; the trial simply stops and is never charged automatically. When you subscribe, the first payment is taken that day and then automatically on the same date every month (every year for yearly plans). You can cancel any time from the customer page; the plan stops at the next renewal date and can be used until then. No pro-rated refunds.
- Disclaimer: this service has no connection whatsoever with any organization that runs soroban tests. It does not guarantee learning results. If something is broken we will fix it, or refund the fee for the period it could not be used. We accept no liability beyond that.
- Copyright: the app's text, diagrams and workings belong to the operator; the sound effects belong to their source (Kouka-on Lab). The illustrations were made with generative AI.
- Changes and ending the service: if the content changes or the service ends, we will say so on this site in advance.
- Governing law and court: Japanese law applies, and the Maebashi District Court is the court of first instance for any dispute.
Effective 12 September 2026
Contact
Families and schools alike: email [email protected]. We reply within 2–3 business days. Questions about plans, the trial, cancelling or your data are all welcome.
To cancel or change your credit card, you can also go straight to the customer page.