Asagiri Yohko is an ordinary high‑school student who loves a boy who is unaware of her feelings. To express her emotions, she writes a song, which turns out to contain more than just a few lyrical bridges. While listening to her own composition, Yohko is transported to Earth's other‑dimensional sister world, Ashanti. The song holds the power to open a gateway wide enough for a conquering force to invade both worlds. This danger was recognized eons ago by the legendary warrior Leda, who forbade the song. Now, Leda’s duty passes to Yohko and a group of new friends, who must stop the onslaught and return the two worlds in...