After plunging into a lake, Lan wakes up in the body of a girl thousands of years in the future. Yet, she never forgot her promise to him. Across space-time, “he” has the same appearance as “him”, but “he” is no longer human, and “he”… is no longer “him”.They say love in this lifetime is a repaying of debt from the previous one.When the rain falls and the meadows burgeon with blossoms blue as the sky, who still remembers the language of the flower, and who cannot let go?