Kenshi Usagi was one of the four retainers of the Excalvur Family.
Kenshi was a renowned samurai long before he became a retainer of the Excalvur Family, although he was independant from the Dominion.
It is unknown when he became a retainer of the Excalvur Family. During his time as one, he fathered a single daughter and trained Angel-Ion, Lance and Setsuna in the ways of the sword, teaching them his very own Rabbit Style in the process, with Angel-Ion being his most adept pupil. He also taught these skills to his daughter as she got older.
Kenshi was apparently killed during the Assault on the Enoshima Family by Doriru Agobiar in a cowardly move. His apparent death rendered Angel-Ion, Lance, Setsuna and Yabira as ronins.
Angel-Ion would later pass down some of Kenshi's teachings down to Luther Visarion, including his Rabbit Style. His sword and cloak were later taken by his daughter so that she may carry on his legacy. Angel-Ion also passed down his teachings to his apprentice, Shin Hitomi.
He wore a cloak which beared a purple hood which was made to resemble bunny ears.
While he was considered rough and hurtful, Kenshi was caring of both his only daughter and the three children of the Enoshima Family. He often insulted and teased his pupils.