Scarlet Empire

Story : 
Kotetsu Miyasaka is a kendo prodigy. While his twin brother, Yayoi, practices the sport, though, he lacks his sibling's skill, enrolling in a different school to try and differentiate himself. When things go wrong at Yayoi's new school, though, Kotetsu finds himself caught up in a potentially life-or-death confrontation -- only to suddenly find himself swept back to Edo period Japan where the stakes are infinitely higher!

Taking in by Souzou Sagara and his roshi band of samurai, Kotetsu must find a way to survive in the past and possibly help shape Japan's future!