Kyou mo Dokka de Hachimitsu ga Nurareteiru Kyou mo Dokka de Hachimitsu ga Nurareteiru

Nishu's older sister was murdered by an assassin known as the "Dentist." Determined to avenge her, she plunges into the underworld herself. However, she ends up clashing with her partner, Fujimi, over a certain matter, and then...? (Source: MANGA Plus)