The terrifyingly powerful mushi within Yui is on the verge of losing control and consuming her. To prevent this calamity, Kiito and friends need to find the mother of mushi, the legendary “oldest girl boss in Japan.” But Yui manages to get to her first, while in her White form! Will Yui be able to overcome this fearsome foe, or is she in over her head? Find out in the thrilling conclusion!