Jun Poo is an alien crew member whose spaceship crash-lands into Hazumu Osaragi on Mount Kashimayama, causing Hazumu's physical transformation. As part of the alien group tasked with reconstructing Hazumu's body, Jun Poo is directly involved in the incident that forms the series' central premise. Jun Poo reappears during a Christmas-themed OVA set four months after the main events, demonstrating ongoing ties to Earth and the main characters. This alien return coincides with Hazumu's continuing emotional challenges and relationship developments.