Jun is a headstrong person who is childhood friends with Tomo. He is very childish in many ways and doesn't get several simple premises as his strength is more physical. He moved from Tokyo to the town where Tomo lives.
He had dated Misuzu for three days in middle school before breaking up with her. He also likes Tomo after not seeing her for years, but doesn't notice her embarrassing attempts and cannot convey his own feelings well enough to understand. He treats her as "one of the guys."