Higashidani Ōta is the younger brother of Higashidani Sanosuke and the youngest member of the Higashidani family. Rather small and weak at the age of six, Ōta spends a great deal of time being protected by his older sister Uki, but learns the value of strength after finally meeting his long-lost elder brother, even adopting the "Aku" symbol Sanosuke wears on his back. In the 15th year of Meiji, Ōta journeys to Tokyo and becomes a student of the Kamiya dojo.