Sakuya Shiina lives with Kanade, her male cousin and foster parent. In times of pain and sadness, she's always taken comfort in looking up at the stars. One day, a mysterious boy suddenly shows up at Sakuya's house for her birthday. He leaves her with kind words, but she has no idea who he is!

All she has to go on is his name--Chihiro! Not one to let that deter her, she sets out in search of him with the reluctant help of her two best friends, Yuuri and Sei. Everyone says that Sakuya should just forget him, but she's oddly drawn to the curious boy. Then, a twist of fate allows them to meet once more! Will this meeting bring them closer together... or will the feelings between these lone stars remain forever in the dark?