User blog comment:SodaCat/Birthdates According to Graduation Year/@comment-2099017-20160124020917/@comment-1824274-20160124201708

I think he's a sophomore. He's already 15 when the game begins, and the normal age for freshman is 14-15, and the typical age for a sophomore is 15-16. I think Jimmy may have a summer birthday, considering his birthday is not mentioned in the duration of the game and he's 15 for pretty much the whole game. It would make sense.