Kumokawa Seria

Kumokawa Seria (雲川 芹亜) is a side character in the Toaru Majutsu no Index series. She is a third-year student attending A Certain High School and is described as a genius. She's currently employed by Kaizumi Tsugutoshi, one of the twelve members of Academy City's Board of Directors, as his advisor.

Appearance
She is considered to be a "beauty senpai", with her shoulder-length black hair, with her fringe tied back, her height and her very big bust.

She normally wears the school issued sailor uniform, with the change of a long-skirt which looks like it had strong defenses. One could see her bellybutton in the gap between her blouse and skirt. She definitely looked smart, and was definitely athletic.

Also, it seems like she didn't need to worry about money, only needing red tea to go along with cake. Though she's an adolescent, she could taste the difference between brandys, and even if she drove around in a red sports car, she won't look out of place. Of course, the latter descriptions were just an impression others would get when they look at all.

Background
It is unknown when and how Seria became a "brain" for a director but in a conversation with Director Tsugutoshi, she apparently chose to be an upperclassmen with a school life meaning she had a different form of occupation.

Personality
She is considered to be a very manipulative and calculating person who thinks of the big picture many times. Often than not, people whom she works with feel she is a force to be reckoned with. At other times she can be seen as aloof or arrogant in her manners (something which got Fukiyose Seiri very angry). She seems to enjoy teasing people at times, once saying that Seiri copied her looks.

She's very knowledgeable in things happening on the Science side, knowing about Deep Blood, Imagine Breaker, and the Level 6 Shift project. Personally she's very interested in Touma and his ability Imagine Breaker.

Volume SS2
She proposed using the SISTER clones that's going through "adjustment" in various parts of the world to collect the 50 or so 'gemstones' and keep them under their protection, so as to resolve the issue of governments and/or various other agencies from forcibly taking control of natural born espers, or 'gemstones', to try and build another esper research facility (even though according to her the chance of them discovering a way before they end up killing the gemstones like lab rats is zero) opposed to Academy City, It is implied she made some sort of deal with Heaven Canceler in order for the SISTER clones to be mobilized. .

It is also implied Seria knew Kamijou Touma from before his memory loss.

Battle Royale Arc
She's also mentioned in passing in Volume 19, when GROUP needed an ally on the Board of Directors to fight against the Director after them they ruled out Kaizumi as a option, since Seria would not be fooled easily and might advise Kaizumi against helping them.

Homecoming
She meets Touma again when he returns to the city but heavily intoxicated, she is one of the group of girls that follow him back to his dorm only to later leave. It is revealed that during his absence from the city she became lethargic and commented on being regretful neither she nor the director Tsugutoshi could help out Touma despite the fact they had power. After an attempt to reengerize herself, she commented she couldn't keep such appearance even for a conversation as it was hollow and she was not like Shokuhou Misaki. This means both the directors and Seria know the truth behind the #5 Level 5.

Seria is the main character of a short story named Love Letter Contest (ラブレター争奪戦) found in the artbook Rainbow Spectrum: Colors by Kiyotaka Haimura, in this story she set ups a plan on where she will catch a spy by using a love letter from her to Kamijou Touma, under the logic that the spy will believe the love letter to be an actual important confidential message from Seria to Touma; for this purpose Seria creates a great ruckus and makes it quite know that she wrote a letter to Touma. At the end of the story not only Kumokawa catches the spy, but it is also slightly hinted that she is aware of Touma's memory loss.

Abilities
Her powers and related abilities are not known as of now, though she is shown to be an extreme planner, in that she orchestrated a plan to catch the spy by using a "love-letter" to deliver to Kamijou Touma, so as to create a ruckus and let the spy think she is delivering secret documents.

She is also said to be an expert in the usage of hynoptic suggestions, making her enemies fear her and create a mistake if they panic.

Quotes

 * “Kumokawa Seria, the Super JK Tactician bossed around by the Board of Directors, is here!! I’ll dull the judgment of any pure boy☆!”