Arishima Naotake

Long ago he had a fatal disease. He used to work at a big hospital but no matter what treatments he took, nothing worked on curing his disease. While he was despairing over the fact, Alice’s mother essentially beat him up and dragged him to Monobeno saying that she knows a famous doctor. Which was Tooru’s father. In the end Naotake got his disease cured and thus owes his life to Tooru’s father. That was one of the contributing factors to why they decided to settle down in Monobeno.