Sakuya Shiina resides with Kanade, her male cousin and foster parent. During moments of pain and sadness, she consistently finds solace by gazing up at the stars. One day, a mysterious boy unexpectedly appears at Sakuya's house for her birthday. He departs after leaving her with kind words, yet she has no idea who he is! Her only clue is his name--Chihiro! Unwilling to be deterred, she embarks on a search for him, aided reluctantly by her two best friends, Yuuri and Sei. While everyone advises Sakuya to simply forget him, she feels oddly drawn to the curious boy. Subsequently, a twist of fate enables them to meet once more! Will this encounter bring them closer together... or will the feelings between these lone stars remain forever in the dark?