One day, your average joe university student, Kashiwagi Yuuya was summoned to another world by a stupid goddess. His mission is to do what any cliche Isekai MC does; become the hero, get the harem, defeat the demon lords, save the kingdom/other earth and go back to earth. After doing all those menial shit, he was granted to go back to his original world with only a second passed despite wasting 3 years in his "hero" life. Expecting himself to be an average joe again, much to his surprise, he still retains his powers as a hero. It seems his mission is just not over yet. It's an isekai but not an isekai but technically an isekai? Just read it to find out! From the popular web novel is now in manga form! WN Raw:

Misaki Marei is a second year in high school, and she sucks at studying. She has no real goals in life, and has zero interest in taking the college entrance exam...until her childhood best friend, Micchan, says she's going to college. Now Marei has found her goal: pass the entrance exam for Akamon University, an elite college, and go to school with Micchan. (tagged both shoujo ai and yuri for now because it's not clear to me which is accurate / more accurate. several Japanese Amazon reviews of this manga mention "yuri", but we all know there's no distinction made in Japanese)

On her 12th birthday, Angele is infected with the strange and fatal disease that causes feathers to sprout from the body. She is sent to a solitary institution to be quarantined where she meets a man named Hakana and the wheels of fate begin to turn.  (Source: Mangaupdates) Based on the free game from Niconico.

A mysterious man butchers his way through a busy train car in Tokyo. This marks the starting point of a series of mysterious incidents.  Renji Amamiya is attacked by Toriko, a prostitute with whom he is in love with, but he is saved by father Mitakura, a renowned exorcist who reveals to him the existence of demons...

A story where a girl of light fights against the darkness of the world.

Licht, a young man who has the special ability, [Resurrection], makes his living as a member of an S -Rank Adventurer's Party.  However, the King, who feared his power, ordered his comrades to betray him, and in the end, executed him in an unfair manner. But Licht, who was fortunate enough to be revived because of his own skill, now swears to carry out his revenge on Humanity…

Gunji Akira, who has just started high school, has been chasing after his father's ghost by trying to become a police officer just like him. One day however, he has a surprise encounter with an alien while leaving school. And there begins the start of his fateful adventures with extraterrestrial life... Note: It runs in a seinen magazine and will not be BL. At most, just as Fujobait as any shounen sports manga.

This is the story of the daily lives of two women from different worlds. Yuria is a renowned model who can’t seem to resist protecting her manager, Okabe, from other guys making a move on her. Both live inside a romantic comedy, hiding what they feel for one another.

Office worker by day, pink lady at night and her third face... deadly! She is beautiful, dangerous and determined to clean-up her city from the scum that cross paths with her. Follow Yuki in her adventures as the Pink Salon Sniper!

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!

Ryutaro Saeki (32) was divorced and return to living alone again. He is quick to find a suspicious cheap property, but in that room, he was greeted by Zashiki Warashi. Bizarre and funny life of two people living together will start !

A tale about a modern deep-sea aquarium employee in Tokyo! What's living in the overwhelming darkness deep within the sea? Take a glimpse into this strange world about a boy working at a deep sea aquarium.

A 32-year-old single mother is told by her neighbor, a university student around 20, that he likes her. Thing is... he's not particularly shy about why he likes her.

Shimazaki Mako used to be a zebra, but she hated her life of being chased by lions, so now she's turned into a human. But in the apartment next door is a former lion...!? It's wildlife survival of the fittest for these former animals turned high school girls on Kami-sama's whim.

The Sage Dwight, he along with the Hero defeated the Demon Lord who sank the world into darkness. However, they were falsely accused of becoming the next Demon Lords because of his power, and were thrown to The Valley of the Dead to die....... But though his flesh has rotten away, he lives on as a skeleton because of his grudge against the world. Dwight has vowed to deny that wrong world, and with a power that surpasses even the Demon King of the past, and also leading countless Skeletons he's going to start an all out war...!

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)

I, Hayato, once met an Oni princess when I was young, and I made a promise to marry her when I became eighteen. But after that day, I was predisposed to experiencing ecchi disasters whenever I touch women.  With the cause unknown, I intended to live out my life in high school without ever finding a girlfriend. But on that faithful day, Sakura, the Oni princess grown up, came back as promised. This is the tale of an Oni Princess x High School Boy and the mystery of the ecchi Curse Charm that circles them.

The workplace comedy's story follows a 26-year-old office worker named Momose. He recently changed jobs after his previous boss harassed him. He's worried his new boss will also use power harassment to make his life miserable. Momose is trying to hide his anxious stomach when he first meets his new boss Shirasaki, however he's surprised to find his new boss is such a natural airhead that he eliminates all of Momose's anxiety.

A cool model and a manager’s romantic comedy begins!

Our protagonist is a college student who enjoys playing as the evil-aligned faction Arachnea in her favorite real-time strategy game. One day, she finds herself in a world similar to the one in the game; additionally, her body is now that of a fourteen-year-old girl. While things are a bit different from how they were in the game, one element has remained the same: she is the leader of the Arachnea. The insects under her control, collectively known as the Swarm, praise her and implore her to lead them to victory. In order to survive, she raises her Swarm and forms friendly relations with the elves of the neighboring forest. But after a slaver traveling through the forest murders one of her Swarm and the nearby kingdom's knights burn down the elven village and massacre its people, she prepares to launch her counterattacks in the name of revenge. However, revenge is merely a pretense for attacking the countries of this world. Her command is masterful and severe, as one who has played the game in real life… ---

The manga tells a fictional version of the story of historical Tang China diplomat Wang Xuance, centering on his diplomatic journey from Tang Dynasty China to the Empire of Harsha in India in the 7th century CE. When he comes upon a crumbling empire that is now hostile to him he escapes to Tibet and raises a confederation of Tang, Nepalese, and Tibetan soldiers to mount a raid on the Empire of Harsha.

About a tanuki girl in Osaka who wants to be human.

The "Great War of Heroes," in which the hero and the demon king vie for survival and power in each incarnation. The fourth great war was also a war where the heroes defeated the Demon King… it's an undisclosed fact. Twoeight, the ace of the “Agency” in the dark side of kingdom, undertakes all the dirty work for country and supports the Hero to subjugation the Demon Lord from shadows. As the unsung hero, Twoeight hopes to live a peaceful life after the war. However, defeating the Demon Lord is not enough to bring peace to the world. This is a story about an awkward boy who is a former “behind the scenes” agent. Fights, opposes, and tries as hard as he can to protect his daily life. Original Web Novel: https://ncode.syosetu.com/n2133fo/

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.