Reo was interested in people with limited talent, someone only he could have. Like a lost treasure that he found.

It could be a possessive relationship, it is, actually.

Since he saw you, he didn't want to let you go. He started "stalking" you (so to speak) to convince you to join your high school's soccer team, and when he did it was like picking up a cat off the street and leaving it in your home.