The Umaki Clan was a powerful and prominent Senshi clan who's influence was outdone only by the Shimonseki, with whom the Umaki Senshi apparently had a strong connection to, the two clans possibly being long-standing allies. When the overlord of the Shimonseki, Arisaka, led his own clan in a revolt against Emperor Shigeru under the belief that the Emperor was attempting to destroy the warrior sect's dominance over the lesser classes, the Senshi of the Umaki rose alongside him and combined their forces with the Shimonseki to storm and conquer Ito and kill many of Shigeru's Senshi supporters. During the Battle for Nihon-Ja, however, upon witnessing Shigeru's willingness to sacrifice his position to ensure peace, the Senshi of the Shimonseki and Umaki stood down and took up Matsuda Sato's chant of the Emperor's name, abandoning Arisaka before presumably returning to their territory under Shigeru's rule
Though unconfirmed, it is speculated that General Todoki, an ardent supporter of the Shimonseki warlord, might have been a member of the Umaki or even potentially their leader, which might explain why the Umaki were the first clan to join the Shimonseki in their overlord's revolt. If this is the truth, than Todoki's crest - a green ox - might possibly be the symbol of the Umaki Clan.