Trinita was Hanae Orikasa's cat. She saw her master talking with a "student with red marks on his arms" moments before her death and escaped to the street, but was soaked in blood. Trinita was eventually found in a bloody state by Rohan Kishibe and Koichi Hirose, who found Hanae's body after looking for Trinita's master. Trinita was kept at the police station during the investigation, but was retrieved from there by Koichi so Rohan could use Heaven's Door on the cat and find clues about who was the killer. Koichi then took Trinita back at the police station.