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Watanabe Mari (渡辺 摩利) is a student of National Defense Academy, and was a Year 3 student in First High School who served as the Public Morals Committee Chief. She is one of the "Triumvirate", the three strongest, most talented students at First High School.
Appearance and Personality
Mari is a young, beautiful woman of average height with short black hair and brown-gold eyes, though her features and aura caused her to be called a quite handsome, young woman. She is one of former Student Council President, Saegusa Mayumi's, closest friends. The two of them always were together, and are partners-in-crime when they are doing something mischievous together, like teasing or forcing others into doing their orders or anything else.
She was appointed to be the Public Morals Committee Chief because of her tough, disciplined, sporty personality and excellence at combat. Mari has the aura of an older sister, and is called by her 'subordinates' during her leadership in Public Morals Committee as 'big sister.' She always became angry when called this way due to her dislike of the term, especially when the ones who used it are the same year as her. (This might be because it is a term used by yakuza henchmen when addressing the mistress of the boss of their organization.) She is also called, 'Boss', proof of her bossy and charming leadership. (Or yet another Yakuza reference to how her subordinates view the way that she runs the committee.) However, her leadership skills apparently did not extend into organization, maintenance, and paperwork, as she was inclined towards leaving that to Shiba Tatsuya, whom she and Mayumi forcefully recruited.
Mari is a strict, resilient, and outspoken young woman. She is of the same type as Chiba Erika, except Mari is a bit more patient in handling matters. She is known to others to act a bit rough and harsh, however this is not the case when she is with her boyfriend, Chiba Naotsugu, as she will become a soft girl who melts away in front of him.
She is 168 cm tall and weighs 54 kg. 
Mari is not of the main family and is the only one of her family with vaunted magical talent.
She started her years at First High School at the same time as Katsuto and Mayumi, and three of them, being notable talented magicians at the school, became popular as The Big Three of First High School.
Mari is a combat magician who specializes in anti-personnel Magic, boasting first class magic combat ability as a Year 3 Magic High School student. Her advantage over others lies not in overwhelming magic power or swift activation speed, but in her versatility in multiple magics and her ability to combine them to simultaneously chain multiple magics, a high class technique that is extremely difficult for her opponents to defend against. At First High, Hattori Gyoubushoujo Hanzou might possess a similar ability, but in terms of anti-personnel combat, Mari's complexity and versatility put all others to shame. Her expertise lies in striking at exposed sensory organs, such as auditory and olfactory senses in order to take away an enemy's fighting ability using magic. Thanks to these skills, Mari is able to stand shoulder to shoulder with Magicians who are direct descendants from the Ten Master Clans like Katsuto and Mayumi. The three of them together were known collectively as the "Triumvirate".
- A famous Magic technique passed on exclusively by Genji swordsmen. However, in the age where magic had become public knowledge, Dojigiri has suddenly vanished, becoming an ability that researchers are aware of but have not witnessed with their own eyes. The original name of this technique is Multiple Slash but was replaced with Dojigiri in order to hide the identity of the attack.
- The twin blades in Mari's left hand releases a small short blade which is thrown towards the desired target's head. Meanwhile, Mari wields two thin strings in her left hand like a weapon. Along the direction of the swing, the string emits the repulsion edge Pressure Slash. The twin blades, when falling upon the target's head, also emit Pressure Slash along the edges of the blades. The thin string in Mari's hand can then exceed the speed of her twin blades thanks to the application of Gravity-Type acceleration magic. This three way attack is impossible to dodge completely. Even highly skilled magicians like Tatsuya or Lu Ganghu are no exception to this fact.
- Mari didn't actually formally receive training in learning this Secret Sword of the Genji. She accidentally stumbled across this after perusing the contents of ancient texts left at home and had Naotsugu assist her in training and somehow ended up learning it. Since the "Genius of Magic Close Combat", Naotsugu, helped her in learning this sword technique, her version of this includes Pressure Slash, unlike the original version. Because of her house's situation of being at the tail end of the Watanabe Family, the knowledge of her ability to use this technique isn't well-known since it would arouse some problems.
➨ Pressure Slash
- Thanks to training and learning from Chiba Naotsugu, Mari tends to use this Weight-Type Magic to reinforce and lengthen her bladed weapons from the created thin repulsion field.
- In combination with chemical dust thrown at the opponent during combat, Mari uses Absorption-Type Magic to prevent the rapidly "burning" carbon particles inside the dust thrown previously from interacting with heat and light but allows them to quickly interact with oxygen around the opponent's airspace. The result allows much of the oxygen to be converted into carbon dioxide. In a flash, the air will become thin around the opponent's position and thus gives the opponent a state of oxygen deprivation.
- Mari uses Magic to control the air flow and currents to allow chemicals wafting from small containers in her possession to be combined and mixed for an assorted arrangement of effects such as drunkenness. This can then be sent as a smell into the opponent's nose that leads directly to various organs. This airborne attack is used in order to incapacitate an enemy or lower his/her combat capabilities.
- Commercial Aromatherapy relies on the powerful effects on emotions caused by smells. Mari can send perfume wafting through the nose into the olfactory cells, hereby combining a scent that lowers mental resistance and another which controls the consciousness to create a literal truth serum. This was used on Sekimoto Isao in a holding cell when she visited with Mayumi and Tatsuya sometime before the Scorched Halloween incident. She also tried to use it on a captured bipedal tank pilot during the Yokohama incident, but without any results due to the perfume being too weak. This was due to her previous interrogation of Sekimoto and the ban on carrying chemicals during the interrogation, which happened exactly on the morning of the incident.
- Mari uses various scents to directly provoke emotions and memory. This theory of using scents had already been medically proven in the previous century.