Tsuzuri Tessou (鉄装 綴里 Tessō Tsuzuri) is a character first introduced in A Certain Scientific Railgun and is a recurring character of the series. She is a member of the Academy City security organization Anti-Skill and is a subordinate of Aiho Yomikawa, but is very incompetent and bad at her job.
Tessou has long green hair which is often shorted down by having it put in a ponytail. She also has lime green eyes and wears glasses over them. Her usual attire consists of a blue vest with dark blue shirt and pants with black combat armor with the Anti-Skill emblem placed on the front whenever she is in combat and has a tan dress as her civilian cloths and wears the blue vest whenever she is out on patrol. Tsuzuri appears to be rather young as if she were in her 20s.
Tsuzuri is a very kind hearted, nice, and well-intentioned individual wanting the peace and security of Academy City's citizens. Tsuzuri is very clumsy and dimwitted on countless occasions and is incompetent as a member of Anti-Skill. Despite this, she is still deployed into combat zones and even fired her weapon while closing her eyes closed.
- Marksmanship: Tsuzuri has skills with handling firearms being an Anti-Skill Officer. Tsuzuri however, is very incompetent and once open fired with her eyes shut but is still able to use a gun including an SG-550 Assault Rifle.
- Civilian Handling: Tsuzuri is very skilled and well handling in terms of civilians. She is very social and can talk with people well but can gulible at times. This is shown when she told Kuroko Shirai, Mikoto Misaka, Kazari Uiharu, and Ruiko Saten at an arcade and told them to go home but they convinced her to play a game with her instead. Since the four girls liked her, Tsuzuri appears to be very appealing towards civilians. Another example is when she befriended a boy who was an avid player of her favorite game Gekisho and played it with him and the two of them bonded.
- Gaming: Tsuzuri is a professional at the game Gekisho. This is demonstrated when she showed an unnamed boy who played it a lot how to be a certain character in the game and what skills are needed. The two had a little bond over the game as a result of her skills at it.