Owner is a dog that was collected by Maika Sakuranomiya when she sees him abandoned in a cardboard box with a message asking to adopt him. However, as Maika can not keep it at home, Owner was eventually sent to live temporarily with Dino.
Owner is a smart dog who can convince his master when he wants to go out. When Dino refuses to take him outside, Owner approaches his collection of figurines and threatens to eat them. He often wants to leave very early in the morning, which inconveniences Dino, who often gets up late because he watches anime during the night.