Niiyama Toshiya is a composer, arranger, bassist, and manipulator. Focused on piano and bass from an early age, he gained experience supporting various bands as a bassist before starting his work in composition and arrangement. Specializes in music styles such as denpa songs and Kawaii Future Bass. Approaches every project with a spirit of challenge and creativity. As a manipulator, he has worked with artists including Ayaka Wada, the Up Up Girls group, and Atto-kun.