Privacy Policy

Last updated: September 7, 2026

This policy explains how CDC Co., Ltd. (株式会社シーディーシー) ("we", "us") handles user information in the app and web service "MACS Nihongo" (the "Service").

1. Information we collect

The Service does not collect information that identifies you personally, such as your name, address or phone number. No account registration is required.

Word lists and study progress: stored only on your own device.
Photos (only when you use the AI scanning feature): images you take or select are sent, through our relay server, to an external AI service (Google Gemini API) so that the words can be extracted. Images are used only for that processing and are not stored by us.
Random device identifier: a random identifier is generated per device and sent with scanning requests, to prevent abuse and to count usage. It does not identify you personally.
Payment information (Premium subscribers only): payments are processed by Stripe. Your card number and security code never pass through us, and we never collect or store them. We only keep the customer ID and subscription ID issued by Stripe, together with your subscription status and next renewal date. If you enter an email address at Stripe's checkout, Stripe holds it and uses it to send you receipts.

2. Purposes of use

Extracting Japanese words, readings and meanings from photos
Preventing abuse and managing usage limits
Processing Premium payments, determining subscription status, and providing cancellation

3. Third parties and external services

Google (Gemini API)	Image analysis
Google (Cloud Text-to-Speech)	Japanese pronunciation audio
Cloudflare	Hosting for our relay server and website
Stripe	Payment processing (Premium subscribers only)

We do not sell or otherwise provide user information to any other third party. We do not serve advertising and we do not perform behavioural tracking.

4. Retention periods

Word lists and progress (on device)	Kept on your device until you delete them
Images you send	Not stored (discarded after processing)
Usage counters	Daily counters are deleted after roughly 26 hours; monthly counters after roughly 40 days
Subscription status	Stored against your Stripe customer ID and deleted automatically about 400 days after the last update

5. Children

The Service is intended for learning and may be used by children. We do not knowingly collect personally identifying information from children.

If you are under 18, please obtain your parent's or guardian's consent before subscribing to Premium.

6. Your rights

You can erase the data on your device at any time from within the app, or by deleting the app. To request disclosure, correction or deletion of data held on our servers, please contact us below.

7. Changes to this policy

We may revise this policy. Material changes will be announced on this page.

8. Contact

CDC Co., Ltd. (株式会社シーディーシー)
Fuji Bldg. 2, 7F, 1-4-32 Minamimorimachi, Kita-ku, Osaka 530-0054, Japan
info@cdcsoft.co.jp