As per Google Play's app-account deletion policy users can request their accounts and associated data be deleted by sending us a message from their app logon email address.
We will confirm the email address associated with your account and send a confirmation to that email account to delete all the data we hold for your account.
Please note you will still need to uninstall the app from your device to complete all data deletion on the device.

Alternatively you can delete all your account data in Sukiru from Settings > Delete your account.