As a child, Gundham lived with his mother; his father was likely absent. Though he and his mother seemed to have a good relationship, his mother was terrible at cooking. This later became the basis for Gundham's belief that his body is brimming with poison. He explains that he couldn't refuse to eat her food because that would make her cry, which prompts Hajime to think that Gundham is actually a "really nice guy."
Gundham never liked crowds and large groups, and he suggests he dislikes being touched by other people. In elementary school, he regularly skipped Sports Days and never held hands with other children. During his FTE, he says that the nurse was "a member of my tribe," so he camped out in the infirmary to avoid social interaction.
He has many other animals at home, cared for by individuals he chose to assist with breeding duties. Gundham also claims to run a website about the dark arts containing dangerous esoteric knowledge disguised by breeding information.
