Executioners on the Bakumatsu

I would like to know how can I find info about a ronin by the name
KawaKami GenSan , that fought for the Meiji during the Bakumatsu.

He was a superb swordsman of the Shiranui Ryu school and seems to
have been killed after the restoration by his former allies (he
wasn't satisfied with the Meiji politics).

Any information about he or his school, or means to get it, will be
greatly welcome.

Kallikrates