Rurouni Kenshin Vol. 4 (manga)

Shinomori Aoshi was once the leader of Edo Castle's elite guard, the Oniwabanshû. But with the fighting at an end and the shôgunate overthrown, the brilliant Aoshi and his four most loyal onmitsu, or spies, find themselves without a home or a purpose. When fighting is your life, loyalty to those lost ideals (and to the man who most symbolized them) may be the one thing left. But Megumi's life is at stake, and however sympathetic Kenshin may feel, he will fight on, to the last man if necessary...