In YE 30 Ketsurui Uesu, the former emperor, fled Yamatai at the head of his personal fleet. Officially Yamatai has had no contact with Uesu or his followers. Secretly, he has been in contact with the Ketsurui Clan for years, and Yui has begun to worry about the new empire he may be constructing. This is the voyage of the YSS Heartbreaker. Its sole mission: discover the true fate of Uesu's Fleet.