Kae has been taken away and Kawaki must face a dangerous assassin. Himawari acts as his partner and provides support during the battle. They try to corner the enemy with coordinated attacks, but the enemy proves to be powerful. Meanwhile, their classmates, who had entrusted Kawaki and Himawari to directly confront the assassin, take action in a desire to try to help. Will Kawaki be able to save his precious friends and accomplish his mission?
