The Book is a minimal spa located in Tokyo, Japan, designed by ciguë. The Book, a cosmetic and healthcare brand, wanted to create a spa with an ethereal and ambient atmosphere. The floors consists of glossy black epoxy resin, off-white polished concrete, and oak. The walls are complemented by plaster stucco, polished concrete. The staircase consists of vibrated aluminum and stainless steel with plaster soffit.