OVA
Description
Shizuka Tachibana suffers profound personal tragedy when her fiancé, Eiji Kuraza, becomes a demon after consuming a drug created by a pharmaceutical company. This transformation costs her an arm and ignites her quest for answers and vengeance.

She seeks out Tsunami Shijo, a guardian specializing in demon extermination, requesting he locate and eliminate her transformed lover. Shizuka actively participates in investigating Eiji's transformation and the demonic threat plaguing Neo-Shinjuku. Her path intertwines with Tsunami's mission to confront demon leader Takamiya, who killed Tsunami's lover (depicted as his mother in the manga) and schemes to enslave humanity.

Her journey culminates in confronting Eiji in his demonic form, an encounter laden with emotional weight due to their past relationship. This outcome highlights the tragic consequences of the drug and demonic influence. Shizuka evolves from victimhood to active engagement against supernatural threats, partnering with Tsunami against Takamiya's forces.

Differences exist between the anime OVA and manga portrayals. The anime, set in 2089, depicts her losing her fiancé and arm, seeking answers and vengeance, and joining Tsunami's mission. The manga, set in February 2019, shows her directly approaching Tsunami (who runs a detective agency) to find and exterminate Eiji, explicitly linking his transformation to the pharmaceutical company's drug. The manga also details post-terrorist attack radioactivity in Shinjuku influencing the setting. Climaxes differ: the anime features a battle in space, while the manga concludes with a grounded confrontation where Takamiya mocks Tsunami using his mother's body, ending as Tsunami destroys him with fire powers in an explosion.

Her appearance, personality beyond her drive for answers and vengeance, involvement in other media, and background prior to these events remain unelaborated.