Kajin was raised as a prince from childhood, as his father left home and never returned. He grew up as a ruffian and bullied those who were weaker than him. Kajin became lazy in his training as he grew older, indulging in alcohol, drugs, and women, but he was still a lazy genius. At age 29, Daven beat him. He could not accept that the person he considered an ant, whom he had harassed and humiliated, had become strong and had seen him. Kajin secretly loves him.