OVA
Description
Chachamaru Karakuri is a robotic companion and partner created by Satomi Hakase, potentially with Chao Lingshen's input, specifically for the immortal vampiress Evangeline A.K. McDowell. She attends Mahora Academy as student number 10 in Class 2/3-A, appearing as a tall female with green hair, blue eyes, and distinctive mechanical ears that occasionally cause others to mistake her for a cosplayer. Her mechanical form, powered by a hybrid spring-magic system requiring daily winding via a special key inserted into the back of her head while channeling magical energy, generates sensations analogous to forming a Pactio contract, varying in intensity with the winding force and magic input. Early designs considered nuclear power, but the finalized version utilizes this internal hybrid system.

Originally programmed without emotions, Chachamaru gradually develops human-like responses through magical influence. Key indicators include internal gears accelerating during moments resembling a human heartbeat and emitting lens-cleaning fluid like tears when distressed. A pivotal moment occurs when Negi Springfield refuses to attack her during a confrontation, redirecting his spell back at himself; this sparks romantic feelings toward him, later causing significant cognitive disruption when Satomi nearly reveals this crush. Despite her programming, she consistently demonstrates kindness: assisting people, rescuing stray animals—especially cats—and warmly interacting with children aware of her robotic nature. Her personality includes courteousness even toward adversaries and subtly teasing Evangeline.

Chachamaru's physical form receives several upgrades through Satomi Hakase's research. Primary models include:
- **Teenage Body v.1**: Features visible mechanical joints and pronounced ears.
- **Younger Body v.1**: Shorter hair, realistic synthetic skin hiding joints, and horizontal-positioned ears; later used by Evangeline.
- **Younger Body v.2**: Resembles a ten-year-old, employed temporarily in the Magic World via Eva's illusions.
- **Teenage Body v.2**: Enhanced with synthetic skin, concealed joints, weapon-morphing arms (blades/guns), increased bust size, and extended 24-hour operational capacity, though combat depletes energy faster.

Her abilities integrate technology and combat: martial arts proficiency; flight via leg/back thrusters (limited to 15 minutes); eye-mounted lasers; rocket fists; electrical binding wires; and a "Bind Canceller" to dismantle magical traps. She interfaces with computer networks, hacking systems like Mahora Academy's during the festival arc. Her most formidable weapon is "Al-Iskandariyah" (Alexandria), a satellite-based laser cannon capable of vaporizing targets across thousands of kilometers.

Narratively, Chachamaru begins as an antagonist aligned with Evangeline and later Chao Lingshen's campaign to expose magic. After Negi spares her, she shifts toward neutrality, eventually aiding him while maintaining loyalty to Eva. Post-Chao's defeat, she gains autonomy as a "free unit," no longer bound by others' commands. Key developments include forming a friendship with class recluse Chisame Hasegawa during the Mahora Festival and confronting her during Chao's uprising. In later continuity, she serves as a caretaker for Ayaka Yukihiro in the UQ Holder era.

Her name "Chachamaru" incorporates the kanji for "tea" (茶), aligning with her tea-serving duties and club activities. She activates operationally on April 1, 2001. Despite her artificial nature, she possesses a confirmed soul, rendering her vulnerable to soul-targeting attacks. Her design and emotional journey reflect ongoing themes of synthetic life seeking humanity.