I've met one person in my life who may or may not have masturbated. She is Korean and about 90% fluent in English, for background.
Anyway, a couple of my friends (including her) were hanging out and somehow the subject of masturbation came up. When we mentioned it, she was like "Wait...what's that?". We all started explaining it to her, but she got very uncomfortable and tried to change the subject so we stopped talking about it. We've never talked about it again. So I still don't know whether or not she's never masturbated before, or if she didn't know the English word for it, or what. It was pretty surprising, she never seemed sexually repressed or anything before that. ¯\(°_o)/¯
Butbutbut...the internet tells me that Asian girls are the horniest...