Garu is a character from the game Nu: Carnival, voiced by Kuroi Isamu. He has an alternate personality, named Karu.
Official description from the game’s website:

A magical wolf beast turned man, Garu lives his life out in the wilderness. Both pure and simple of heart, in order not to lose his ability to speak human language during his years in solitude, he started to have conversations with himself. Ultimately, in those wild and unforgiving conditions, he developed a second entirely different personality.