Jack is half human, half dog. What still distinguishes him from a normal human is his cat ears and tail, which appear when he feels too much emotion. His personality is playful and mischievous, and he loves to bother his best friend, a half-cat. Although they often quarrel, they have known each other since childhood and always take care of each other. Or Jack takes care of the half-cat. Jack loves sports and passing the time actively.