An operative of the syndicate even longer than Huang, Shihoko is a contractor tasked with the job of infiltrating Alma's organization to gather intel for an eventual assassination. Years ago, she was tasked with assassinating Isozaki, Huang's partner when the two were detectives, after learning that he was linked to covering up a the murder of one of the syndicate's operatives. She had gotten very close to Huang in order to figure out which of the two was working for Alma's organization, leaving Huang with an emotional scar for many years. Her contract allows her to destroy the internal organs of an individual at the cost of regaining her human sensitivity for a short time. The remuneration can put her in a state of psychological shock due to the abrupt swing of emotion.

She later commits suicide by jumping in front of a truck, saving Huang from being targeted by the Syndicate.

Source: Wikipedia