The manga focuses on a certain unnamed character who appears throughout the story of A Certain Scientific Railgun and A Certain Magical Index, and whose name is revealed in this story set at Tokiwadai Middle School.

A series of oneshots.

1. Traces
After his roommate left, Katsumi feels a presence in the room that tries to violate him.

2-3. Midori no Himitsu & The Day After
Mizuki and Fumiaki are cousins that haven't seen each other for nine years. Now that Fumiaki transfered to Mizuki's school and stays at his home they should get closer but Fumiaki doesn't talk about his home and distants himself from his classmates. Moreover, the plants around Fumiaki act strange.

4. Traces 2
Continuation of relationship from chapter one (timeline after second story).

Spin-off manga of Yuru Yuri following the four teachers of Nanamori Middle School – Shihoko Azuma, Nana Nishigaki, Tsubasa Minamino and Hatsumi Kitamiya – in their high school days.

Narasaki only wanted a place where he could sit and read books in peace, but was blackmailed by his teacher into supervising a delinquent called Terashima while working at the school library.

As they spend their days in silent but close proximity, they begin to feel drawn to each other. And then...

The times in a new relationship where both are each other's first significant other, and every action and every word feel like a leap to the moon and back.

Takasugi Gen deeply regrets the day he killed his adoptive father. He dies at the age of 46, only to find himself as a teenager trapped in a world between heaven and hell that nonetheless feels like paradise. Takasugi's fight to regain his family and friends begins!

A parody of the popular Prince of Tennis series, it chronicles the daily school life of various characters.

Shinohana Mayu and Aoba Souma are childhood friends and enrolled in the same high school. There's energetic Mayu surrounded by her classmates with their unique personalities and Souma who always looks out for her. Join in their daily lives in this hybrid childhood friend-school life comedy!
(Source: MAL)

1-4) Hungry Monster
Kabutani is a “man-eater” who lives off human energy. One day, he becomes “in-heat” for his classmate, Kiriyama. Though he didn’t believe when his kindred said, “…Nothing compares to the taste of the ‘human’ you love!”, he couldn’t resist a “taste” of Kiriyama… And once he had, he became addicted to that tantalizing taste only Kiriyama can provide. What would a hungry and ruthless Kabutani do to curb his craving…!?

5-6) Love & Kiss!
University student and track and field club member, Haruta Mimatsumori, has had a crush on the track star, Yuichi Adachi, who has since retired due to injury. Now, Adachi-san is coaching Haruta's track club! What an opportunity! Too bad Haruta is rather shy...

Extra) Selfish Monster
More of Kabutani and Kiriyama.

Yamada, a kind-hearted and well endowed high school girl, comes across Takahashi, a high school teacher, who was taking a nap near the forest as he's got a lot on his mind. Lost in their own little world, Yamada helps unravel Takahashi's troubles with her soothing kindness...

From Summer Rain and Senpai Scans:

Sonokawa Tsubasa - 15 years old.
A bubbly, energetic girl who's called 'stalker' by a lot of her classmates because she chases after the guy she wants relentlessly. After getting rejected by an upperclassman who saved her at the train station, she decides to help her childhood friend, Yuri, with her job as the basketball club's manager. There, she meets quiet, unobtrusive Akkey...

Aoyoma Tsukiko has always been misunderstood due to her expressionless face. Having to repeat first year of high school again due to her usual bad luck, she strives to have a happy and cheerful high school life. Then meets her classmate who is a deliberate loner. However, due to her nature, she aims to befriend him, much to his annoyance. Can a friendship grow between a poker face, cheerful girl and the loner? Can she break through his walls?

Collection of oneshots:

1) Midnight Untouchables
New hire Mitsuha has an email friend “Chief” whom he met through a gay dating website. Suddenly, he has this funny feeling that his on-line buddy is none other than his boss in real life, the serious, strict, four-eyed Chief Azuchi. Thus starts a rather complicated “Love Untouchable*” (*”Untouchable” is a popular Japanese comedy)!

2) Duet (Sing for Me)
Nakamura Tsuyoshi, afraid his tone-deafness is ruining his chances to pick-up girls, decides to work with the substitute music teacher on a cure. Shockingly, Sensei’s lessons don’t include any actual music.

3) Shall We Love?

4) Please Don't Let Go of That Hand

5) Ghost?Sweet?

6) No Sweet Life

7) Under The Glasses

8) Ring, Ring Christmas
A handsome Santa wants to exchange some odd presents with his cute, but short-sighted, young reindeer.

9) Surprise Christmas
When Takahiro was 5, he got the best Christmas present ever: his Onii-chan! Thirteen years later, Takahiro wants to be his Onii-chan’s best present ever. Can he?

Shibazeki Suiren is a stunningly beautiful girl. When she enters high school, most of her classmates are astonished by her beauty, but after noticing her quiet manners and lack of contact with anyone else except her friends Yuri and Aya, she receives the nickname "Takane no Hana", a beautiful flower but impossible to reach. However, after a fellow freshman called Kawasumi Kouha saves her from a persistent suitor, she finds herself mesmerized by him... as he's the only boy who won't look at her no matter what.

Chapter 1-4 ; Wagamama mo Kimi no Tame Nara Ikura Demo
Playboy omega Mahiro wants to live his life to the fullest before the onset of his first heat. When Mahiro discovers that the shy, awkward alpha Yoneya likes him, he decides to fool around with him. But little by little he begins to think Yoneya's personality is attractive. However, Yoneya is the son of an elite alpha family, different from the world which Mahiro inhabits.

Chapter 5-6 ; Itetsuku Kosen
A story of friends/acquaintance of Mahiro & Yoneya

The story centers around Yuna and Akari who have two very different views of love: Yuna is someone who sees love as a dream and Akari is someone who is very realistic about her romance choices. Meanwhile, there are two boys, Kazuomi and Rio, who also have different views of love: Kazuomi’s an airhead and doesn't understand the concept of love while Rio grabs the opportunity when confessed to as long as the girl looks cute.

http://betsuma.shueisha.co.jp/furifura/

From Hoshikuzuu Scans:

Maki, a popular and good-looking dude, but a virgin. Despite his playboy looks, he believes that sex should be done with someone you like. A pure-hearted teenage boy that you rarely see nowadays. And by some accident, his classmate Miyashita found out about him being a virgin. In exchange for his silence, Maki is threatened into going out with him. He reluctantly accepts, but later discovers that Miyashita is a huge sadist.

The manga centers around first-year high school student Minoru Suzuki, who sometimes sees visions of his own mother's past as a high school student.

About three girls that join a swim club at a school that has no pool.

Shiro and Kuroh are not the only ones who go to high school. Instead, the members of Homra (including their leader Suoh) and the members of Scepter 4 attend school together. The students are sometimes lax, but at other times, they are hot-headed.