Rumi is the fierce leader of the Kodama team, said to be the strongest in the investigation bureau. However, as a reaction to having to push herself too hard in the male-dominated world of SPs, she has a hidden personality of an intense masochistic woman, contrary to her outward appearance as a scary, sadistic, big-breasted SP. A mysterious psychological counselor approaches her and cleverly finds his way into the gap in Rumi's Kokoro, leading her to engage in extreme S&M play in the name of an aptitude test.