The Tome of the Night Sky (夜天の書 Yaten no Sho, officially/Ger. Buch der Nachthimmel) is the device type::Storage Device (being part of reprogrammed Reinforce) used by Hayate Yagami in the end of A's. It is also the new Storage Device she creates post-A's (in the autumn of 0069) based on the design of the original one, and uses in the subsequent series. Prior to this creation, Hayate co-uses with Reinforce Zwei a similar Storage Device named the Book of the Azure Sky, which is solely used by Rein after the new Tome is created.