During his past Otowa was the friend of the shadow ninja Nakajō, who he had nightly competitive killing sprees with. He said that he joined Enishi's campaign because of Nakajō's death while fighting Hitokiri Battōsai; in reality Otowa joined the fight just for pleasure
Otowa is avery sadistic man. In his few appearances he appeared to take great joy in the pain, suffering and killing of others. His sheer cruelty extends to even women and children, who he kills with equal glee.
Despite his bravado and glee of killing he is a bit of a coward as he almost retreated from the Kamiya dojo attack after Kenshin simply glared at him.
In a battle with Yahiko in the attack on Kamiya dojo, he takes the boy lightly and while he comes close to killing Yahiko a few times thanks to his sneaky tactics the boy eventually defeats him.
As he's defeated he has a crazed smile on his face as he could not believe he would be defeated by someone not even half his age with even less battle knowledge. He was arrested by the police afterward and never appeared again.
A tall thin man, who's most striking feature appears to be his love for lipstick, makeup and nail polish. His clothes appear very feminine as does his hair his most prominent suit trait is the six long piercing tentacle-like appendages worn on his torso. He appears to be a drag queen but it was never reveled if this was a lifestyle trait or if it was another of his his diversionary tactics.
Skills and abilities
is a master of assassin's weapons. His skill lay not in his skill so much as their hidden nature; he has them hidden all over his body.
He claims to have thirteen in total yet only managed to use four during his appearances.
The first is Baika-Chusen- a small arrow-launcher worn on his left wrist. This is used in tandem with a mark on his right palm, thus while the opponenet watches the right arm he attacks with the left. He has used this to great effect causing soem to think he knows magic.
The second is the Kasui Busuen- a paralyzing mist generated by dropping two small cubes into water. He ised this the first time he met Kenshin so he could make his escape.
The third is a jar of iron powder (Bishamonpun, 'Bishamon's Powder'), used in conjunction with his "enchanted" Bishamonken ('Bishamon's Sword'). To make up for his lack of sword skills he sprays the opponent with metal powder then magnetizes the sword so the sword's edge is attracted to the opponent giving him the impression of great speed and skill.
The last is the Rokudouko- six long piercing tentacle-like appendages worn on his torso. If all his other techniques don't work he can spring a sneak attack with these appendages to finish them off.
His battle tactic is to outwit the opponent and catch them off guard with his hidden weapons as opposed overpowering or out fighting them with pure skill.