Testicle kicking fetish (Tamakeri)
Tamakeri (玉蹴り)(lit. ball kicking, AKA ball-busting) is a sexual fetish and subgenre of pornography in Japan. In tamakeri pornography, a female kicks a man in the testicles. Some tamakeri fetishists report that they prefer to witness kicks that resound with a hearty slap. Pornographic tamakeri videos cater to masochistic men for whom the idea of getting their testicles kicked is sexually stimulating, at least in fantasy.
Erika Nagai is among the few AV performers who work in this kind of fetish.