Kessai Kiyoshi

Kessai Kiyoshi (潔斎 雪紫) is a student of Tokiwadai Middle School who appears in Toaru Kagaku no Railgun. She is the former roommate of Misaka Mikoto and a member of the Hasekura Clique, one year before the main story.

Appearance
Kessai has dark-colored hair, with an exposed forehead and prominent eyebrows. She wears the Tokiwadai Middle School uniform.

Personality
Kessai seems to get along with Mikoto (addressing her as 'Mikoto-chan'), though she is secretly monitoring her for the Hasekura Clique.

Jailbreaker Arc
Some time after her battle with Shundan Kimi, a hospitalized Misaka Mikoto briefly thought back to her time with Ruri and Kessai while observing the interactions of her similarly hospitalized friends.

Kessai herself has yet to appear in the present day.

First Year Arc
Kessai joined Tokiwadai Middle School in the same year as Misaka Mikoto, one year before the present, and became a member of the Hasekura Clique. Being assigned to the same room at Mikoto, she was tasked by Asato Kisa with monitoring the Level 5.

In early May, following a swimming class, she explained the circumstances surrounding Shin'enkouji Rurikakesu and Tokiwadai's three main cliques to Mikoto after mentioned her earlier encounter with the former. Leaving for her club, she accidentally left behind an accessory, which Mikoto noticed after she had left, and in trying to contact her to return it during the day, encountered the three clique leaders and a few others. Kessai had a phone conversation with other clique members regarding Mikoto, before receiving her accessory back in the evening, when both had returned to their room.

At some point after the switch to summer uniforms, Kessai witnessed an argument between Mikoto and Shokuhou Misaki. After listening to Mikoto describing her first encounter with the other Level 5 and thinking about the circumstances while they walked down a street, the pair encountered Ruri who accompanied them to Vending Machine 7116.

Abilities
Kessai's unnamed ability appears to allow her to discharge steam from her body. As a student of Tokiwadai Middle School, it can be presumed to be at Level 3 or 4.