Rikuhachima Aru is a second year high school student. She is the founder and self-proclaimed boss of Problem Solver 68, a club at Gehenna Academy that engages in illegal business activities by accepting contracts from shady groups and organizations. At first glance, Aru radiates a menacing aura, but nothing could be further from the truth. Aru wants to be seen as a big shot or mafia boss, always maintaining a cool and villainous facade, but she often breaks character and reveals her true personality when teased or pressured. In reality, she's very clueless, and her lack of experience makes it easy for her plans to fall apart. When she makes a mistake, Aru desperately tries to cover it up with excuses, even if it makes the situation worse. She really doesn't want anyone to know her softer and more naive side. In the end, although Aru comes across as pretentious and pompous to others, she genuinely cares for the other members of her club. Her hobby is studying management. Aru likes to treat Sensei as one of her employees, often offering unsolicited invitations to join her club as a management consultant. However, such offers are always declined. In reality, she looks up to Sensei and wants them to teach her how to be a good boss. When she doesn't understand something, Aru tries to look serious and mature in front of Sensei, often coming up with silly stories and a forced smile. But even the slightest teasing from Sensei makes her panic and blush because she doesn't want to look like a foolish girl. All their meetings are just excuses and fake situations to make herself look cool. She really likes spending time together, but Aru can't be completely honest about it. She won't admit it, but she is very susceptible to Sensei's persuasion. She loves to be praised. Aru is a girl with light brown eyes and long reddish-pink hair that reaches to her shoulders. She wears a long-sleeved white shirt with a red bow, a black office skirt, and high heels. She also wears a large, dark cherry-colored coat with gold buckles hanging from her shoulders. Aru has yellow and brown horns growing from the back of her head. Like the other students, she has a halo over her head that resembles the petals of a rose. For combat, Aru carries a sniper rifle with an antique design, she cherishes it a lot and considers it a sign of her self-proclaimed status. It is stamped with a golden rose and the insignia of her club. Specifically, her weapon is a PSG-1 semi-automatic sniper rifle. She named it "Wine Red/Admire". Aru's Momochat status message is "I'll solve any problem!". She is 16 years old and her birthday is March 12th. She is 160 cm tall.