The Book (stylized in all caps) is the debut extended play (EP) and first physical release recorded by Yoasobi. It was released on January 6, 2021, the same day with their seventh single "Kaibutsu", through Sony Music Entertainment Japan. "Encore" serves as a promotional single of the EP. Ayase, a member of the duo, also released the cover version of The Book, on the same day as the EP, titled Mikunoyoasobi, recorded by Hatsune Miku, exclusively at Tower Records Japan. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.