this is naga, invited along to help translate. a custom service company but he also teaches pole dancing for men. then there's this man, kinoko, one of the best-known and respected practitioners, a master of shibari, the art of ropes, of beautiful knots, of what for lack of a better word we call bondage. so how big is the sadomasochistic community? how many people are active participants? >> translator: 100,000 people. >> a lot? >> a lot. >> this is shubari, translation, to bind. and to make things more confusing for those looking for a concise takeaway, a comfortable reaction for what sure as hell looks pretty disturbing. tomika, who spends most of her time whipping, burning, and generally abusing men, enthusiastically reverses roles in her longtime relationship with hajami. it looks like a very delicate procedure. does it hurt? or does it feel good? >> translator: this pain change to the necessity. she said when she was tied up, no need to think. just leave it to -- she love it. ♪ >> performance art, craft, fetish, or compulsion