Kyoichiro is obsessed with his little sister Mutsumi, practically being a stalker, and would do anything in order to protect her. As a result, he's extremely overprotective of her, and will do anything to keep others away. His methods include threats and blackmail to even torture and murder; especially if those people are boys. He is also very affectionate towards her, often trying to spend time with her and being overly caring and doting.