TERMS OF USE
Terms of Use
Tokinaoshi / Established November 15, 2026 / Last revised November 15, 2026
These terms are the rules for using the iPhone app “Tokinaoshi” (ときなおし; the “App”) provided by Ryo Tsuzukihashi (independent developer / TsuzuKit; the “Developer”). By using the App, you are deemed to have agreed to these terms. This English text is a translation for convenience; if it differs from the Japanese text, the Japanese text prevails.
Article 1 (Application)
These terms apply to everyone who uses the App (“Users”). The App is distributed through the App Store, and Apple's standard license agreement (EULA) also applies. If these terms and the EULA conflict, these terms prevail.
Article 2 (About the App)
- The App is a set of practice questions for studying for certification exams. The exam included at first is the Data Scientist Certification, Literacy Level
- The App is not affiliated with the exam organizer (The Japan DataScientist Society). It is not official study material
- The questions and explanations were written by the Developer for this App. They are not questions from the actual exam
- There is no account registration or sign-in. The App is for iPhone only
Article 3 (Price)
- The App is a paid app bought once on the App Store. The price shown on the App Store is the correct one
- There are no in-app purchases, subscriptions or ads. No additional payment is requested after purchase
- With the same Apple Account, you can download the App again without paying again when you switch devices or reinstall
- Refunds follow Apple's rules. Please request one from Apple Support (reportaproblem.apple.com). The Developer cannot issue refunds directly
Article 4 (Accuracy of the questions)
- The Developer has the questions solved again by a separate reviewer and checks them so that the questions and explanations are correct. Mistakes may still remain
- If you find a mistake, please report it from “Report a Mistake in This Question” in the App. After checking, it will be fixed in an update
- The exam scope and system may be changed by the organizer. Please check the organizer's official information for the latest details
Article 5 (Prohibited acts)
When using the App, you must not do the following.
- Anything that violates laws or public order and morals
- Copying, reprinting, distributing or selling the App's questions or explanations without the Developer's permission
- Disassembling, analyzing or modifying the App
- Obtaining or distributing the App by anything other than the proper means
- Anything else the Developer judges to be inappropriate
Article 6 (Intellectual property)
The rights to the App's questions, explanations, screens, illustrations and name belong to the Developer. Where sentences from the Society's Skill Checklist are shown on screen, they are credited as “一般社団法人データサイエンティスト協会 スキルチェックリストより引用” (quoted from the Skill Checklist of The Japan DataScientist Society). “データサイエンティスト検定” and “DS検定” are trademarks of the Society.
Article 7 (Data)
Study records are saved on the User's device and in the User's own iCloud, and the Developer does not hold a copy. If they are lost because of device failure or loss, deletion of the App, iCloud settings or other reasons, the Developer cannot restore them.
Article 8 (Disclaimer)
- The App is provided as is. The Developer does not warrant that the App is free of errors, that it is always available, or that it fits a particular purpose
- The App does not promise that you will pass the exam. The “target” in the mock exam is not a figure that guarantees passing
- Even if a User suffers damage from using or being unable to use the App, the Developer is not liable except in cases of the Developer's intent or gross negligence. Where the Developer is liable, the liability is limited to the amount the User paid for the App
Article 9 (Changes and termination)
The Developer may change the contents of the App or stop providing it. When these terms change, this page is rewritten and the revision date above is updated.
Article 10 (Governing law and court)
These terms are governed by the laws of Japan. For disputes about the App, the court with jurisdiction over the Developer's address is the exclusive agreed court of first instance.
Contact
ryo.tsuzukihashi@tsuzukit.com