He is Kenshin and Kaoru's son, appearing at the end of volume 28. He enjoys climbing but cries when he can't get down. He loves his mother but doesn't like his father, often pulling Kenshin's hair.
In Samurai X: Reflections, he remains a toddler, though some scenes jump to when he is fifteen years old, training with Hiko. In the OVA timeline, Kenji grows up without Kenshin's presence, witnessing his mother's ongoing sorrow over his father's absence. This leads Kenji to resent his father's selfishness and his mother's continuous depressions.
At age 15, Kenji runs away to Kyoto to train under Hiko Seijuro XIII in the art of Hiten Mitsurugi Ryu. Showing great promise as a student, much like his father did 30 years earlier, Hiko chooses not to pass on the school to Kenji out of respect for Kenshin. Instead, Hiko keeps Kenji occupied until Yahiko Myoujin arrives to take him home.
Kenji refuses to leave, expressing his desire to achieve true strength and surpass his father's legend. A duel ensues between Kenji and Yahiko. Despite Kenji's potential and genius, Yahiko's experience and wisdom allow him to triumph. After subduing Kenji, Yahiko passes on the Sakabatou to him. Kenji then returns to Tokyo with Yahiko to be with his dying mother.
At the end of the OVA, we see Kenji with a girl named Raikoji Chizuru. Now wielding the Sakabatou, Kenji seems to have made peace with his father.
