The Book For,

The Book For, is the fourth Japanese-language EP (ninth overall) by Japanese duo Yoasobi. Released on June 26, 2026, through Echoes and Sony Music Entertainment Japan, it is the follow-up to the duo's third EP The Book 3 (2023), and served as the fourth and final installment of the "reading CD"-themed The Book series. The EP was solely written and produced by the member Ayase.

12 singles supported The Book For,, including RIAJ-certified singles—Monogatari: Off & Monster Season's theme song "Undead" and 2024 NHK's sport event theme "Butai ni Tatte"—and a collaborative track with Overwatch, "Orion". Commercially, the EP peaked at number seven on the Oricon Albums Chart and the Billboard Japan Hot Albums.