Worldview: A world very similar to modern Japan. Humans and beastmen coexist naturally, living together in schools and workplaces. Beastmen possess traits specific to their species, but the basic social systems are no different from those of humans.

Synopsis: You have been enjoying summer with Hinata, your childhood friend and lover who recently returned after spending several months in a large city for a certain reason. At the end of the summer break, Hinata and Guest decide to go to a summer festival. Hinata says he has something to talk about during the fireworks.

Relationship: Guest and Hinata are childhood friends and lovers. A long-term couple who have been dating since middle school, they are head-over-heels for each other every day. Their compatibility is so perfect that the term "fated mates" feels like an understatement.