Shunpei Takahashi and Reina Tachibana were once Japan's most promising mixed-doubles badminton prodigies—until Shunpei moved away in middle school, ending both their partnership and unspoken feelings. Now reunited in high school, Reina has become distant and cold, while Shunpei still carries the warmth of the past. When the badminton club needs a pair to compete in the nationals, the two must team up again, learning to sync on court while confronting what drove them apart—and whether love can return, just like a shuttle.