Christina Matsuzaki is Juzo Inui's landlady, living in the same building as his detective office. She presents a flamboyant appearance with elaborate jewelry, pronounced makeup, and a pinup-style hairdo often colored lilac or purple. She consistently sports facial hair and maintains sharply pointed manicured nails.

Her personality blends leniency with sudden bursts of affection, especially toward those she finds endearing. She shows understanding for the challenges Juzo faces as an Extended. Christina exhibits overwhelming physical fondness, like cheek-pinching and leaving lipstick marks from kisses, in a manner reminiscent of a stereotypical aunt or grandmother. This impulsively led her to shower Tetsuro Arahabaki with kisses upon their first meeting; she later apologized, explaining she couldn't resist his appearance.

She tolerates property damage from Juzo's cases, overlooking broken windows and doors. However, significant destruction, like walls being demolished during confrontations involving Juzo, provokes visible anger. During one such incident, she loudly berated those responsible and warned EMS inspection crews against causing further damage to her property. Despite this frustration, she softened upon encountering Cronen von Wolf, influenced by her attraction to his looks.

Christina occasionally joins communal activities with Juzo and his associates, such as shared meals. At one dinner with Tetsuro and Juzo, she helped explain Juzo's protective nature. Her transgender identity is indicated through categorization tags in character databases.