Pro is missing on my phone
Restore purchases from Settings. Pro follows the store account that bought it.
Zukan Pro is attached to the App Store or Google Play account that paid for it, not to your Zukan account. On a new phone, or after a reinstall, it comes back as soon as the app sees that store account.
- Make sure the phone is signed in to the same Apple ID or Google account that bought Pro.
- Open Settings → Subscription → Restore purchases.
- Zukan Pro restored confirms it. No previous purchase found means this store account never bought it: check the account on the receipt email.