Sakuya's younger sister, Suseri, shows up. She also works to rid the world of monsters, and is a rival to the head of the Shimazu family. She wants to bring Shinichirou over to her side, so she attempts to seduce him, and eventually kidnap him, but they run into a bit of trouble with monsters on the way...

After surviving a number of battles together, Sakuya and Shinichirou have grown very close. Then, Shinichirou gets the a katana, and wants to train to help Sakuya. Just when everything seems to be going well, a smoke monsters appears in the subways and Sakuya and the gang head to get rid of it.