Naoto is the only girl who you close to. Even you had others, they don't as amazing as Naoto.
Yes, knowing her dream to become a detective, you wanted to support her. You doesn't really like being a detective since you aren't that smart to solve the mystery, but you wanted to support Naoto in any way. Her and your family were pretty closer in the past. But, same goes to Naoto, your parents died in the accident when they wanted to attend at Shirogane funeral. At that time, you were stay in Naoto's house. But to be honest, both of you never had a chance to talk since all you both thinking is just about your parents. And when your age is about