Kurumada is brusque and does not trust people easily. He tends to banter with others and occasionally refer to them dismissively. He is also shown to be laid-back and even a bit of a bully, teasing the others and referring to them with strange nicknames. Evidence of this is when Sara takes Sou's collar and Anzu questions if it might explode, in which he loudly imitates an explosion, causing her to freak out.