In the 1860s in Japan, a new era is dawning. During this time fraught with violent social upheaval, samurai of all walks of life flock to Kyoto in the hope of joining a band of warriors united around their undying loyalty to the shogunate system. This group becames one of the greatest (and most infamous) movements in Japanese history...the Shinsengumi!

Sei devotes herself to becoming an ideal bushi, or warrior, and accompanies the Mibu-Roshi to Osaka. There, she finds the man responsible for killing her father and brother. Desperate to avenge her family, Sei uncovers his hideout with the help of a friend, but they are soon discovered and her companion is slain. Is Sei ready for the hardships of the Mibu-Roshi? Or should she return home to lead the life of a normal girl?