Kazuki inadvertently reveals his identity as an Alchemist Warrior to the Hayasaka twins, members of the L.X.E. (League of Extraordinary Elects), when he activates his Buso Renkin in front of them. After Tokiko and Kazuki take on the twins in a late-night battle, they learn the location of the L.X.E. headquarters, and head there along with Captain Bravo. Intending to put an end to Dr. Butterfly's organization, they discover that yet another evil plan has been set in motion...
- Chapter 27: Just the Two of Us
- Chapter 28: Level One
- Chapter 29: A Lot in Common
- Chapter 30: Close Combat
- Chapter 31: Familiars
- Chapter 32: The World of the Hayasaka Twins
- Chapter 33: Don't Give Up!
- Chapter 34: To the Hospital
- Chapter 35: Thirteen Hours to Go
- Chapter 36: Carnival