pathfinder Race help

[Nosta]

I want to play a oni/Japanese ogre but not sure how to go about this
it can just be the flavor but i'd like a size bonus if possible

any ways to make a cool Brawler oni chick?

[Crake]

you could try and homebrew a race with the race points (http://www.d20pfsrd.com/gamemastering/other-rules/creating-new-races/#TOC-Size-Quality) system. A "normal" race is 8-10 rp, large on it's own is 7rp, so that would be pretty much 90% of your race's racial qualities.

[Ninjaxenomorph]

Oni-blooded tiefling? (http://www.d20pfsrd.com/races/other-races/featured-races/arg-tiefling/) You don't get the size, unfortunately. The Big Boned race trait for them might interest you; if you don't want to miss out on Enlarge Person, I'd get the Pass For Human racial trait, which lets you count as humanoid for spells. It might be a wash, since you're not visibly oni-related. Alter Self as a SLA isn't nothing to scoff at, though.