This page is available in Japanese only. The Japanese text is authoritative.

Reading offline: a saved book is kept encrypted only inside the browser of that device and cannot be taken out as a file. A save lasts 30 days and is renewed when you are online. Books you bought and members’ books: any number (up to 3 new members’ books a day). If you lose a device, remove its saves from My books on another device.

Pages of publishers' books: when you first open a page in the reader, we record the time and a sign of whether a person's input (key, touch, mouse or wheel) came just before, or whether the browser seems to be driven by a program (two small cookies, expiring after 2 minutes and 1 hour, carry the sign). We use it only to count the pages read for paying publishers and to tell automated reading apart; publishers receive only the number of pages per book and month, never who read them.