Based on the Shin Megami Tensei If videogame.
The setting is Karukozaka High School, which is mysteriously sucked into a void and emerges in the realm of Makai, a world of demons. Most of its students and school employees are trapped in the other world along with it.

It's been 18 years since Rin died. Alisa, who is Sei and Lou May's daughter, lives with her mother, her brother Shinji, and Ken in Hawaii. Shinji is Ken and Lou May's son. Shinji knows Alisa isn't Ken's real daughter, but Alisa doesn't. Alisa sometimes sees a phantom boy. One day, she sees a boy point to the sky, where she sees a plane. By the plane, Rie, Shin's son, comes to ask Ken for some help. He also knows Alisa is really Sei's daughter. Alisa is called "Dragon's daughter." Rie says a prophet told him that he would marry a woman who's a dragon's blood relative. When they go into the forest, Rie also sees a boy. Alisa tells him that the boy is a phantom and that he is the only other person who can see him. Her family had told her that the boy was the spirit of the forest, but she doubted that. She thinks the boy is trying to tell her something.

Midori isn't good with people, and at 31 years old, she feels like she has no place in life.
One day, she is attending the funeral of a close friend of hers from junior high school, Tsugumi. Unable to forget about her, she has a vision of the young friend she knew standing above her — only it isn't the girl she once knew, but her daughter, Haruko.

This is the story of the relationship between a woman without a place and a child without a mother.

From Hidoi~! Translators:
Masaki Umeo is a middle schooler with a nasty temper. Because of his temper, he is causing all sorts of problems and is constantly involved in fights causing his sister to worry about his well-being. One day, he stumbles upon an Aikido class which he becomes interested in, but soon dismisses it until he meets Daniel- an english teacher from Canada. Daniel teaches Umeo about the way of Aikido in hopes of giving Umeo a different outlook in his life, but it isn't that simple because there is a dark reason behind Umeo's temper.

A demon school where there is a mean/selfish demon prince who comes school late. He bump into a similar demon prince which cause a commotion or scene. Then the Mean prince notices the demon's prince's friend Eton. Soon the mean prince starts befriending the girl (Eton) and he may even change to a kindhearted demon prince.

This world somehow changed and isn't normal anymore... There's no boys to be found, and all the girls have become...

Super Sonico. Living in Musashino, Sonico's many roles include college student, vocals and guitar in a 3-piece girl band, and gravure model. And now she gains a new title. This is the extraordinary tale of a girl who becomes a few sizes bigger than before.

Twenty year old Ogawa Akira is taking the medical school entrance exam for the third time when he is overwhelmed by anxiety and flees the testing room. He soon finds himself wandering the streets of Tokyo lost and exhausted. Then by chance a woman drops her earring, and he picks it up and returns it to her. He is dumbstruck by her beauty. Overhearing that her name is Kyoko and that she works at the nearby cabaret club, he promptly decides to get a job at the club, with the hope of a getting closer to her and maybe finding his place in the world.

Adapted into a TV mini-series in 2014

If the Earth is destroyed, who do you think would have caused it among us? This is the 18 year old male and female unfortunate survival game. That day, the world looked at us and told us to die.

Qin Fei is an ace agent in a special school. She was betrayed by her partner and lover when she was performing a mission in the Bermuda Triangle. She fell into the sea from the boat and into a crack of time and space, meeting a vampire on first day. The battle of a modern female agent against the ancient "old Draculas" in full swing.

In the mysterious female boss Lu Mansheng's spice shop, occurs many unquestionable fantastical stories of the vicissitudes of life.

Three months after starting college, Gin Fujigaya is still having trouble meeting new people and fitting in. As an escape, Gin indulges in secretly cross-dressing and posting selfies of himself in drag online, which has garnered him a large following. This leads him to going outside dressed as a girl for the first time, and he soon discovers that the way people interact with him like this is vastly different than what he's used to. Over time, Gin's fondness for cross-dressing and looking cute allows him to meet others who are harboring their own secrets.

——Aah, if I had do it all again, I'd rather die.
Adventurer Lughys spent his days as a loser. Opporessed by his party members, so called "comrades", the road to being a hero or a legend was a long ways away. Then suddenly, a mysterious shadow called out for him, giving him the chance to return to his past, and told him he'd be given only one chance.

He longed for it—— This time, he'd obtain valor and honor, and love.

However, the god of fate would not permit it. A battle with a great magical beast, an attack on a noble house, challenging a quest with the hero—— For far and away from his expectations, he gets entagled after rescuing someone. Unbeknownst to him, his dream took a 180, and from the girls in his former party, came a twisted attachment and affection.

There's only one chance at this. ——Now, why not take back the future? Revenge dwelling in a dark, hot flame, and turning the tables in a Replay Fantasy!

This series is an anthology. The following summary is for the first story. All chapters are listed under the same summary despite differences.

SpoilerYukino, who worked as a manager of a cosmetics store, had already achieved her career goal, but still felt empty when it came to her love life.

However, on her off day, she met a lost foreigner, and she ended up spending the day showing him around. She thought he was like a cute spoiled cat… until she was caught by his passionate gaze.

An ardent night of tender caresses and kisses in a hotel suite. They were two strangers, but their feelings were transmitted seamlessly.

From Kirei Cake:

Iride Akatsuki is a popular game footage uploader. He wakes up one day to find that he's been kidnapped and taken to a strange place, along with a number of other uploaders who specialize in different genres of games.

A mysterious alpaca-headed host gathers them after the initial stage, to explain how the game will proceed. Will the group of gamers clear the game and make it back to their real lives?

A producer from 961 Pro has been assigned to work for 765 Pro as a spy and saboteur.

However, the Producer has grown affectionate towards the idol unit he's meant to produce and is struggling to carry out the sabotage missions he's been given, while making sure it doesn't affect the unit too much.

A manga adaption of the video game "THE iDOLM@STER 2".

From MangaHelpers:
Tonight, Natsuo loses his virginity. His partner? Her name is Rui and he just met her today after school. She's the one that brought up this whole situation, stating that she wanted to simply gain the knowledge about sex. She does not want to start a relationship, nor does she care about Natsuo.
Afterwards, Natsuo feels guilty for losing his virginity to a girl he doesn't even particularly like. Mostly, it makes him feel like he betrayed his crush to his high school teacher: Hina. A quirky love triangle story unfolds as Natsuo, Rui, and Hina all end up becoming part of the same family.

Kanei Tomoya came back to his previous high school to be a substitute teacher in Physical Education. He met his fellow teachers on his first day and everything is sailing smoothly until Seta Kousuke came, his arts teacher back in high school. Everything became worse when he accidentally broke Seta-sensei's phone and was asked to be his lover in the span of his four months stay. Now will this "relationship" turn into something good or something bad?

Have you ever felt as if you are a protagonist of a fictional story? Then Ori's life could be called a cruel drama: the death of her parents, uncaring guardians, bullying in school, nervousness around people... But as a matter of fact she is... an invented character in the truest sense of the word! And the author, who decides her future, is already writing a tragic finale! Only, ignorant Ori does not obey his will...