Masaki is a teenage senior high school student, whose boyfriend is 8 years older and his homeroom teacher, Tokuyama-sensei. As teacher and pupil, of course they need to keep it a secret, but both heart and body are carried away in this dangerous relationship because it's a passionate and erotic love!

What if the Meiji Restoration never happened? Bakufu still holds sway, the class system has never been abolished, and there is no westernization. The story is set in modern-era Edo, which had never been renamed to Tokyo, where people go to Kabuki for entertainment and hang out at pancake house. It centers around Sobi, the sister of an Edo magistrate who goes to school with Michisato, who prefers to be called Michel, the eccentric son of the ruling Tokugawa clan's Mito family.

From Fantasyshrine:

1-5) Chokujou Lover's
Iseya Shou is the captain of the kendo club which is about to be shut down due to insufficient members. How far could he go to recruit additional members? Enters the charismatic student council president, Yagami Keishi. How does the manipulative strategist finally capture his guileless target?

6) Your True Face is My Secret

Valentine's Day is coming up, bringing both sweet and sad memories for Nana and Hitomi

Fifteen year-old Ichinose Fujiko works as receptionist in her family's bath house. Since her first love when she was 6 years old, she has not met any boy that makes her heart throb. Miyata-kun saves her little brother from being run over; is he her second love?!

Chii-chan is an elementary school student who is really inexperienced with love. When the new transfer student Rei-kun arrives at her school, her life makes big changes. The next day, when Chii-chan arrives at school, her teacher, told Chii-chan that Rei-kun is dead. What will happen to Chii-chan?

From Scum-Scans:

Chocolat is a mature comedy series about half-orphan Tatsumi Chiyoko whose father was caught in huge debt. Now living with Omugi Matsukichi, an ex-underground king who opened a pastry shop, she gets to know people like Katou Ichigo, an ex-inmate. With people after her father's whereabouts, what will happen to her?

Chizumi is a high school student with Fujiomi, who is her senior by one year. However, the story continues on to when Fujiomi goes to college and Chizumi is still in high school. Chizumi is your average clumsy girl and Fujiomi your hot guy, which makes you wonder how the pair fits together. Indeed, many other characters in the story wonder the same thing and do not hesitate to test the limits of this peculiar relationship.
The first volume includes a short story called April Magic.

The series goes over 3 volumes, each with a different name:
1) Haru wo Matsu Koro
2) Pastel Kibun
3) Gin Iro Ehon

From Esthétique:
Exchange students of boy and girl schools, the start of a confusing and sweet life? Qu You Lin, a national Judo champion, and Yan Ya Qiao, honored as a traditional Chinese music genius, were forced to study in each other’s schools. What You Lin faced at the boys’ school, is a shaky Judo club, useless members, and a runaway coach; Ya Qiao, at the girls’ school, although nicknamed Little Prince Xiao Qiao, can he live surrounded by stars? Both like to go back to their schools, but still like to find new possibilities…

• Clash
A prince at school and at home, Yama is the perfect student. Only when he is alone can he show his true self and his true personality. But, one day, a girl named Saku follows him to his villa and somehow she finds out about his true personality. What will happen now!?

• Extra: Kimi to Iru Kyoushitsu
"When we are together, my heart always tries to tell you; I like you the most...but I am unable to say that aloud, unable to tell because we are just 'good friends'."

Clannad is set in a high-school located in a Japanese town. Tomoya Okazaki is a third-year student who doesn't take his studies seriously. Always late for class, he's seen as a delinquent by the rest of his classmates who are busy preparing for their entrance examinations. Needless to say, he doesn't have too many close friends either.

Tomoya seems not to mind too--until he meets a few other girls from his school. Though he doesn't care much about them at first, he soon opens his heart to them as they get to know each other better.

Clannad is a romantic youth drama that's likely to be more down-to-earth than Key's other works. But like Kanon and Air, Clannad's story is expected to be another touching and heart-breaking weeper.

Based off the game of the same name.

In this school fantasy story set in the distant future, creatures contaminated by pollution have overtaken the land, forcing humanity to live in isolated mobile cities called Regios. One such city named Zuellni is a self-contained school in which freshman Layfon Alseif has just enrolled. Layfon reluctantly joins the 17th Martial Arts Studies Unit led by the third-year student Nina Antalk and embarks on a series of adventures.

This version recounts a slightly different version of Layfon's story.

Volume1
1) Choumaru
Choumaru is a beautiful, smart, and arrogant playboy who dumps every girl he has unsatisfactory sex with. Currently he's living with Shina with whom he also has casual sex, but what he doesn't know is that his roommate wants more from him.

2) Angel

3) Rocker Motion

4) May Be Blue

5) The Cherry Blossoms Bloom

Volume 2
1-4) Scene 1, 2, 3, Last
Continuation of Choumaru. Shina brings home a kid to look after while his photographer friend is away. However, there seems to be many after this child...

5) Born

A series of yuri one-shots.

The first is about two childhood friends who like music and who are asked to perform at the graduation ceremony of their school.

Longing deals with two members of the archery club: Kyoko and her senpai Touko, who is ashamed of her man-like body.

Spice is about a young girls-loving teacher who wants to seduce her female students.

Innocent is about a nude portrait hanging in an art room, the model and the painter.

Rendez-vous is about two girls secretly in love who plan to elope together after being found out.

From Yen Press:

High school student Alice Song has just placed third in Cake Magazine’s manhwa creator talent search. She’s the youngest winner in the history of the contest! Not only does she have her story published but she also gets the chance to work with one of her manhwa idols (who has a surprise for her). And as if that wasn’t reward enough, she’s also reunited with the former teacher who inspired her winning story. What happens when personalities clash and hearts collide like something out of a comic book? Does art imitate life, or is it the other way around?

The normal meeting inside the normal life. The slightly special destiny that becomes entwined inside it.

Come Back Home Story 1: Talent "Do what you do best!" They met by coincidence, a school girl and a delinquent. While she works hard to obtain her dream, will he find a way to use his talent? Come Back Home Story 2: Bride "His name is Bride, a gifted musician. They say he became music's bride because of his immense love toward it. He has never loved anything else other than music. And every concert is a wedding. At the end he throws his guitar toward the audience. Whoever catches the guitar becomes a guitarist as well. The guitar Bride throws, they call it the bouquet." So when I catch his guitar, will I become a guitarist? Come Back Home Story 3: Trick Come Back Home Story 4: Sky Come Back Home Story 5: Idem (4 chapters) A delinquent with a fiery temper and a beautiful girl have known each other for years. While entering high school will their love withstand the problems ahead?

From Storm in Heaven:

Ten years ago, there was an explosion at Hisano's apartment building. She would have been there, but she'd been hit by a bike ridden by a boy in blood-stained clothes. He dropped a fake gem when it happened, and she's been hanging on to it as a good-luck charm ever since. Now Hisano's in high school. One of her teachers was murdered, and the police are investigating. A young man suddenly appears carrying the toy the gem belonged to. And perhaps... can he also see the hallucinations Hisano has always been plagued with? Everything is connected as the pattern slowly rises to the surface.

The Empire of Brittania has invaded Japan using giant robot weapons called Knightmare Frames. Japan is now referred to as Area 11, and its people the 11s. A Brittanian who was living in Japan at the time, Lelouch, vowed to his Japanese friend Suzaku that he'd destroy Brittania. Years later, Lelouch is in high school, but regularly skips out of school to go play chess and gamble on himself. One day, he stumbles on terrorists 11s who've stolen a military secret and is caught by a member of the Brittanian task force sent after them, who is Suzaku. As the rest of the squad arrives, Suzaku is shot for disobeying orders, while the military secret, a young girl, gives Lelouch the power to make anyone obey any order. He takes command of the terrorists and leads them to crush the approaching Brittanian force. However, Suzaku is secretly made the pilot of Brittania's brand new test model Knightmare, Lancelot. Lelouch becomes the masked king Zero to lead the rebellion to defeat Brittania. This series follows Suzaku's side of the story, while Lelouch of the Rebellion follow's Lelouch's.

An alternate Code Geass story in which Lelouch's fate is unknown after his meeting with C.C., whether he be dead or alive. Nunnally makes a Geass contract and gains the power to read the lines of the future. She also obtains a new body and takes up piloting an unusual Knightmare Frame.