A year ago, Takumi lost his wife Mio to an illness, leaving behind their son Yuji and a beautifully illustrated book about her journey to a distant planet called Archive. In the book, Mio promised to return during the rainy season, and miraculously, she does come back, although she has no memory of their past. Takumi is hesitant to reconcile with Mio, doubtful of their connection and his ability to make her happy. However, as Takumi helps Mio remember their history, their love is rekindled. As they uncover the mystery of Mio's journey to Archive, their past and their future become deeply intertwined.
