The protagonist of the series. Her appearance is that of someone in her late twenties, but her real age is unknown.

She usually wears a black suit and glasses. Her whimsical personality serves as a front for a cunning, ruthless mind and extraordinary martial art skills. She always keeps a number of throwing blades and a garrote wire concealed on her body. At some point in the past, a "Fruit of Time" entered Rin's body, effectively making her immortal, unable to age, and capable of surviving and regenerating from a phenomenal amount of bodily damage.

She and Mimi run the detective business Asōgi Consulting together in West Shinjuku,