Also known as: 酸賀研造
A human researcher studying Granutes from Kamen Rider Gavv. He is secretly allied with the Stomach family's scientist, Nylev. Suga is responsible for creating the Valenbuster and performing the surgery on Karakida Hanto which allowed him to transform into Kamen Rider Valen. Using his research into Granutes, he creates the Bitter Gavvs, evil clones of Shouma, as well as finding a way to transform himself into Kamen Rider Bake.