[OOC]

Backtagging: Sure!
Threadhopping: Sure, just ask first if it's an important thread.
Fourthwalling: For this character, I'd prefer not. Kaoru is unstable enough as it is.
Offensive subjects: I'm good with most stuff, but if I'm bothered specifically, I'll say so.

[IC]

SPOILERS AHEAD

Hugging this character: DON'T DO THIS.... Kaoru does not like being touched, especially without permission. Hugging would not end well for your character (and close touching would out one of Kaoru's secrets, which might end up putting your character on the Kill List.)
Kissing this character: Same as above.
Flirting with this character: Definitely fine! Kaoru will allow it, though there probably won't be any reciprocation, unless you count nasty one-liners and insults as flirting back.
Fighting with this character: Go for it! Kaoru goes out of the way to cause this sort of reaction, so it's perfectly fine. Kaoru is stronger than most humans, though, and a skilled swordsman who plays dirty and holds grudges. If your character goes this route, he will remember what happened for a long, long time, and beating him won't be easy.
Injuring this character: Same as above! For any serious injuries, I’d like to talk it over, first.
Killing this character: I’m up for this under the right circumstances, but again, I’d like to talk it over, first.
Using telepathy/mind reading abilities on this character: Feel free! Kaoru has no canon defense for it, though there's a lot of nasty thoughts and memories hidden in there. The most obvious things a telepath will notice are a burning hatred for all of humanity, a lot of memories of murder (both from a third party POV and from Kaoru killing people himself), and an obsession with his idyllic childhood and sister.

[Character information]

Age: Approximately 18-20.
Height: 5'4"-ish.
Build: Slim, but muscular from weapons training and battle.
Hair: Black, cut short. (When in Oni form, it's white.)
Eyes: Brown. (When in Oni form, they're golden.)
Notable features: Rather pretty, often made-up and wearing a pink kimono. Easily passes for a woman, despite actually being a man. He has calloused hands with minor scarring from working with blades. When in Oni form, Kaoru's coloring changes and he has a set of small horns growing out from the front of the forehead that show through the bangs.
Image references: 1. Spoiler images: 2, 3.