Shinji is the reincarnation of Access Time. He is a few years older than Natsuki. He loves to kiss Natsuki whenever she is asleep, thus he was banned from entering the house by Chiaki.
Shinji, unlike Natsuki remembers bits and parts of his time when he was Access Time. He remember the promise of Chiaki of baking pancakes, the earring he gave to Finn when she died and so on.