Tousatsu Harem [best] Guide

Most likely, you’re referring to — meaning hidden camera / voyeuristic photography — combined with “harem” (a group of love interests). If so, that points to a niche adult / ecchi genre where the protagonist secretly observes or photographs a harem of female characters.

It seems you're asking about a “tousatsu harem” — likely a misspelling or shorthand. “Tousatsu” (倒殺 or 討殺) isn’t a standard Japanese genre term, but if you meant or “tousatsu” as in ‘exposure/photo-shooting’ combined with “harem,” I’ll clarify. tousatsu harem