|Gender||Genderless (Female in appearance)|
Ritsu had been programed to act like a very smart, yet friendly figure, and often acts sweetly towards her students. She will try her best to teach her students as well as she could, yet can be rather humble, often blushing at compliments to her attributes.
Ritsu was first created soon after Korosensei and Twilight agreed to make a substitute teacher for class 3-E. Upon creation, Ritsu was put in the class 3-E class. While there, she successfully teaches the class throughout the day, despite having most trouble with Ren Hōsen throughout most of the time spent there. During lunch, Twilight and Akari Yukimura came over to see her, congratulating her on her efforts. She revealed that she can scan students to study their anatomy, and tests it on Akari, finding some odd bumps on the back of her neck. However, she shrugged it off, claiming she 'was born yesterday', and probably needs some more work on it.