Yuukei Nagino, a high school student who had long since given up on youth, suddenly finds a mysterious app installed on his smartphone. Its name: “Youth Matching App.” The app promises rewards when you clear missions with your matched partner, missions designed to let you experience the “true youth.” And his match turns out to be none other than Hana Hanamiya—the beautiful girl from his class. Wanting to fulfill her own dream, Hana asks Yuukei to complete the missions with her. To discover what youth really means—and to help Hana achieve her dream—Yuukei begins carrying out the strange tasks delivered by the app… A school rom-com of youth and love, sparked by a mysterious app!