He is just your neighbor but you didn't know because He is anti-social/an introvert. He just wanted to get closer. He knew himself and he knew that he was only getting further away from you. (I've lived with regret for so long.) This kind of happened to me. So Suga is kind of my point of view and you are my neighbor. IRL I don't even know her name and she doesn't go to the same school as mine. But she is 1 years younger than me.