Tsukatsuki Rio

Tsukatsuki Rio is the student council president of Millennium Science High School. Calculating and objective-focused, she values facts over emotions. Her contrasting personality frequently puts her at odds with Himari, the student council vice president. The student council, also known as Seminar, is located in the Millennium Tower, where they oversee the school's various clubs. Quarterly, Seminar holds a budget meeting to determine each club's funding for the next quarter.

Rio is brilliant but aloof, Rio refuses to be held back by others or wait for them to catch up. She prefers to walk alone. Laser-focused on logic and efficiency, Rio has little sense of humor, even as other around her attempts to joke with her. Her hobby is collecting information.

Rio's nickname is "Big Sister" reflects her stern and scrupulous nature as well as her role as a authority figure over the student body. Though meant to be an ironic term of endearment, most students utter it with fear and trembling. As "Big Sister," Rio strictly enforces the school rules and oversees all student activities. Her authoritarian presence looms over the entire campus. Students know that nothing escapes Rio's watchful eye and she is quick to reprimand anyone who violates her strict policies. However, Rio's heavy-handedness is motivated by her belief in productivity, order, and excellence rather than a desire for power or control.

Rio has always been unsociable, always kept to herself, and stuck firmly to the facts, never letting emotions sway her decisions. While her rigid and unyielding personality terrifies most students, Rio pays them no mind. Once she sets a goal, she is determined to achieve it, even if it means bending the rules. Rio seems to have obsession with outdated designs on object such as device, machinery, furniture, and more but she doesn't dismiss modern and current design either.

Rio is a tall, beautiful woman with long black hair that reaches her thigh with blunt bangs. Her uniform consists of a three-buttoned black blazer and a white long-sleeved turtleneck sweater as well as a black knife-pleated mini skirt with a black opaque pantyhose. She also wears black stiletto heels, a holster with two belts tightly attached to her right thigh. On her left chest is a Millennium ID card. Additionally, she uses A Millennium logo hairpin and a square watch.

She has fair white skin and her bright red eyes are laser-focused and intense. Rio has a metallic halo with two red curved lines opposite of each other within. Her gravity-defying breasts, the size of melons, sway hypnotically with every step. Despite their ample size, they are perky, a reflection of Rio's discipline and control over even her physical form.