Gaku is a tall young man in his early twenties. He has bluish grey hair styled in a slick back manner as well red eyes. He is an extremely calm, nonchalant and laidback individual who always talks calmly and rarely gets agitated or angry, even during fights or life-and-death situations. Gaku often compares real life to a video game, describing a deadly injury as a "speedrun to death". He is very uncaring about the lives of others and can kill without hesitation. He was an orphan at the Al-Kamar.