[He only knows what a katana is because he'd been spending an inordinate amount of time reading about swords lately.]
A favor to be named at some future point will have to do. I don't think I need chores done. [a dry smirk, he barely has any personal effects so there's not much to clean.] I never made one before, but I could try it. Possibly.
Can I ask what you want it for? Self-protection I understand, but if you're planning to kill someone I should probably at least say I asked. [He makes it sound like he wouldn't necessarily say no if it were the latter... but he probably would.]