Blade of the Immortal Omnibus Volume 6 collects Manga Volumes 16-19 and features story and art by Hiroaki Samura.

Rin begins to discover her skills as a warrior and strategist, as she makes new allies and resolves to find the missing Manji. Her immortal swordsman is imprisoned and being tortured in an underground stronghold beneath Edo Castle, however, and cruel doctors hope to find the secret behind his mystical powers. Rin teams up with the enigmatic Doa to not only free Manji but expose the hideous medical experiments.