Seiko Kimura is known as the Former Super High School Level Pharmacist. She attended Hopes Peak Academy in the 76th class, but was expelled before she could graduate. She appears to be around 24 at this time. She is the 5th victim in the original Danganronpa 3 killing game, but that could change in this version.

Seiko is reserved, and has a stilted way of speaking. She understands that people can guess what she is thinking through her facial expressions, so she hides her face behind a mask. She is known to startle easy, and is both quite anxious and shy. Seiko is also compassionate, being distraught at other people's deaths. She is also describes as soft-hearted, taking requests from other people, as well as caring for animals. Because of her soft nature, Seiko is very loyal and forgiving to her friends, unfortunately leading to her being easily manipulated.

Seiko should have a medium low voice for a female, often speaking a little deeply. However, there will be times where she will speak higher, but never going higher than a medium high register. She should be able to display a fair amount of emotion, as tensions are likely to rise around her. She should speak with a little bit of darkness in her, as well as sounding unsure.