A First-Class Detective with the Galaxy Police, she is known as a "genius of coincidence"—inexplicable phenomena tend to occur around her for some reason. She headed to Earth to apprehend a criminal but met with an accident, leading her to become a live-in guest at the Masaki household.

In anime installments other than Tenchi Muyo! Ryo-Ohki, she has a partner named Kiyone. She and Kiyone—who is level-headed (though prone to sudden outbursts of passion)—form a duo whose "straight man/funny man" dynamic rivals that of professional stand-up comedians; their interactions feature perfectly timed banter, complete with Kiyone’s trademark slaps and Mihoshi’s evasive maneuvers.

In Tenchi Muyo! Ryo-Ohki, her partner is Noike Sakutsuki. Their relationship is best described as that of a "highly capable, perfect older sister" (Noike) and a "ditzy younger sister" (Mihoshi).