Terms of Use

Crayon Study: Language

Last updated November 4, 2026

These Terms of Use ("Terms") are the agreement for using the language-learning app Crayon Study: Language (クレヨンスタディ：語学, "the app"), made by Takaki Takemura, an individual developer in Japan ("we"). By downloading or using the app, you agree to these Terms.

Where you got the app from matters as well. On the App Store, your licence to use the app is Apple's Standard End User License Agreement; the rest of these Terms (about the AI, plans, safety and what not to do) apply alongside it. On Google Play, these Terms are the licence agreement, together with the Google Play Terms of Service.

Age

• The app is rated 13+ and is not meant for children under 13.
• If you are under 18, please ask a parent or guardian to read these Terms and agree before you use the app, and to check any purchase first. A purchase made by a minor without a guardian's consent may, under the law, be cancelled; the store's own process applies.
• Dirty mode is for adults (18 and over) only. Don't say you are 18 or over if you are not.

Licence

Provided you follow these Terms and the terms of the store you got the app from, we give you a personal, non-exclusive, non-transferable right to use the app for your own learning on devices you own or control. The pictures, words, sounds and code of the app, and the lessons, dramas and other content it makes, belong to us or their rightful owners.

Your data and your phone

• There is no account. Your records, words, chats, buddy and settings are kept on your phone and are gone if you delete the app or reset the phone; we cannot bring them back.
• The app makes a random ID for your phone, which our server uses to count the day's questions and to keep your chat tickets (see the Privacy Policy).

The AI

• Your buddy, the friends, the teacher and the coach are AI. Their answers are made by AI and can be wrong, out of date or incomplete. They are for learning a language, not professional advice; check what matters, such as for a test, in a dictionary or with a teacher.
• Please don't write personal details about yourself or anyone else in the app.
• The AI follows content rules for a 13+ app, with extra rules for younger learners (see Safety and AI). It may decline a request, and we may change what it does and how many requests can be made in a day, to keep the service safe and running.
• If an answer is wrong or inappropriate, please report it from the flag beside it.

Plans, chat tickets and things in the app

• Plans (Light, Medium and Heavy, monthly or yearly) and chat tickets are sold through the App Store or Google Play, which take the payment; the store's own rules apply, including on refunds.
• Plans are subscriptions that renew automatically: the same amount is charged each period until you cancel in your App Store or Google Play account settings, at least 24 hours before the period ends. After cancelling, you keep the plan until the end of the period you've paid for. Where a free trial is offered, it turns into a paid plan unless cancelled before it ends.
• One plan covers every language you learn in the app. What each plan includes (such as the number of AI questions a day) is shown in the app before you buy, and may change; a change that is to your disadvantage applies from your next period, after notice in the app.
• Chat tickets are used up as you use them, belong to the phone they were bought on, and can't be moved to another phone or restored there. Plans can be restored with "Restore purchase".
• Exchange tickets, clothes and furniture in the app are for your buddy and room. They can't be bought, exchanged for money or given to anyone else. What you have chosen with a plan stays yours when the plan ends.

Ads

On the free plan, the app shows ads by Google AdMob, limited to content rated for all ages. The plans have no ads.

What not to do

• Tamper with or reverse-engineer the app or our server, reach our server other than through the app, or get around the daily limits.
• Try to make the AI produce content against its rules, or get around its safeguards or the age check.
• Use what the app teaches, dirty mode above all, to insult, threaten or harass anyone.
• Abuse purchases or refunds, or break the law.

If we find any of these, we may stop the AI features from working for that phone.

Changes to the app, and ending it

The app changes as we improve it. If we stop offering the app or its AI features, we will say so in the app or on this website at least 30 days before.

No guarantee

We do not guarantee that the app or its AI always works without interruption or errors, that its answers are correct, that it works on every device, or that your data on the phone is never lost.

Limits of our responsibility

Except where caused by our intent or gross negligence, we are not responsible for damage that arises from using the app. Where we are responsible, our liability is limited to what you actually paid for the app in the 12 months before the event that caused it. Where the law where you live (such as Japan's Consumer Contract Act) does not allow these limits, the law applies instead, and nothing in these Terms takes away your rights as a consumer.

Changes to these Terms

We may change these Terms when the law or the app changes. We will post the new text and the date it takes effect on this page beforehand, and at least 30 days beforehand for important changes that are to your disadvantage.

Governing law and courts

These Terms are governed by the laws of Japan. Unless the law requires otherwise, the Tokyo District Court has exclusive jurisdiction in the first instance over disputes about these Terms or the app.

Who we are

• Takaki Takemura, an individual developer in Japan
• Email: [email protected]

The Japanese version of these Terms is the original; this English version is a translation.

Related: Privacy Policy · Safety and AI · Support