YASAI is a Japanese rock band formed in 2017. The band consists of four members: So (vocals), Hayato (guitar), Kosuke (bass), and Yuto (drums). YASAI's music is characterized by its energetic and catchy melodies, as well as its introspective and emotional lyrics. The band has released several EPs and singles, and has toured extensively throughout Japan. In 2023, they released their debut album, "The Blue Hour," which was a critical and commercial success. YASAI is one of the most promising young rock bands in Japan, and their music is sure to continue to resonate with fans around the world.