In Search of the Lost Future is set in Uchihama Academy (内浜学園, Uchihama Gakuen) and with the number of new students at the school increasing every year, a new school building is constructed. Before they move to the new building, the school will hold one last General Club Festival at the old building before it is closed down. Each of the clubs decide to give it their all to make it a success. Sō Akiyama is a member of the astronomy club, and just before the festival begins, the student executive committee asks the club's members to calm the uneasiness among the students in regard to mysterious incidents at the old building. When Yui Furukawa, a quiet girl, transfers late into the school year and appears before Sō, the gears of fate slowly begin to move.