Hida Kizuna possesses the HHG (Heart Hybrid Gear) ability, but it is not strong enough to make him particularly important. His older sister calls him to transfer to a strategic defense school, where many of the students (many of which are large-breasted girls) use their HHG abilities to fight invaders from another world while wearing extremely skimpy pilot outfits. Kizuna's fighting ability doesn't measure up, but his sister has another plan-- apparently having erotic experiences with Kizuna will allow the girls to replenish their energy or power-up. It looks like his new school life is going to be full of embarrassment.

A Boy from an alien planet learns that he is not of that planet. He moves to Earth because of an “immigration project” and now must learn to live among the humans in the scariest place on Earth, Seoul Korea.

Set during the Goryeo military regime, a hero that arises from a slave to be reborn as a general.

Enma's daughter Batsu is looking for help to take down some demons. And who does she turn to...? Normal teenager Takuan! 

Based on Valkyrie Drive: Bhikkhuni PS Vita game.

"A couple of elves, a gnome and an android walk into a bar… Ranial, Thame, Ian and Math, four strangers brought together by circumstance, set off on a series of cybernetic adventures in the wake of a war that has left their world a post-apocalyptic fantasy wasteland. Words by Sam Machado, Art by Cynthia Sousa (Theamat), Colors/Letters by Amanda Sousa Machado, Created by Bradley Mason."

From Storm in Heaven:

Kyu's greatest desire is to become a detective. To fulfill his wish, he goes to take the entrance exam to get into the detective school run by Dan Morihiko, one of the most famous detectives ever! At the exam he meets Megu, Kinta, Kazuma, and Ryu as they all try to pass the grueling three-part exam. Kyu wants to solve mysteries, and he gets his wish: his first real case appears in the midst of the exam!

An Onmyodo School Fantasy of a Failing Private Onmyo Academy Student!!
Tsuchimikado Harutora was born into a prestigious Onmyoji family, but he can't see "spirit energy". Therefore, he's been enjoying a peaceful daily life with his friends at an Onmyo branch school. One day, his childhood friend Tsuchimikado Natsume, heir to the head family, suddenly appears. Will this cause his destiny spring into motion!?

Failed on his job-hunting, shut-in Sagara Kurohiko went to the mountain on the day of a typhoon where he is struck by lightning and dies. But he is still alive, in a strange land with a great holy tree. To his surprise, his physique has rejuvenated to when he was teen. Brought to the academy near the tree, he is soon suspected as a spy from another country, and was brought to the headmaster. An accident happened on the way, which enraged the headmaster. Before Kurohiko can get blasted by magic, his eyes laid upon an old parchment. He took it and read the contents. Suddenly four holes appeared and black chains came out from each of it, binding the headmaster. It is then revealed that Kurohiko just recited an incantation of "Forbidden Art," an art which is extremely powerful from a legend. Apparently, no one has been able to decipher the contents of the scroll, which makes Kurohiko the only current Forbidden Spellcaster. Sparked by this, the headmaster offers Kurohiko to attend the academy.

The setting of Devil Survivor 2 spans the whole country of Japan. It tells the story of Japanese high-school students who receive emails from a website foretelling their friend's deaths. Mysterious creatures invade the country, and the students enter a pact, enabling them to summon demons from their cell phones with a special Devil Summoning App.

This manga is based on the horror-style exploration/ero-game of the same name. Reiichi heads off for a part-time job interview, hoping to get money for a new bike, and his self-styled servant Kuro-senpai tags along. The "interview" is in a western-style mansion, but no one seems to be around. The two of them end up locked in the mansion and must find their way out.

From MangaHelpers:
One day, Serizawa fell asleep at work and had a dream about a past love that he wronged when he was in middle school. On the way home, he was involved in an accident, and a woman who knew him called for an ambulance. Now the woman has his phone number, but he doesn't know her identity. Serizawa thinks back over the women he has loved in the past, trying to determine who this woman that has re-entered his life is.

In the whole world there lay a mythical creatures which have their own ecosystem and can’t be considered part of the food chain. They also have supernatural powers and live together with humans. Ferry is one of the professional investigator, who researches the connection between the creatures and humans and is called a Genjuu Chousain (Mythical Beast Investigator). The story starts when a flying reptilian dragon (Wyvern) is attacking a village, and a Girl dispatch on the quest to research and investigate Wyvern and other mythical creatures.

From generation to generation, the Oike family has handed down the vocation of exorcising a cursed box. This bizarre fantasy weaves humans and phantoms into a story revolving around Miyo Oike, a descendant of the Oike family.

A story about a new enthusiastic teacher, Naoki Sakura, who took up his new job in all-girls high school! He became the homeroom teacher of the first years, but the girls in the class contains full of different personalities. He declared to these girls "I want all of you to love one another!" Will he and his students be able to build a teacher-student relationship with that goal!?

In the year 21XX, robots are a typical part of everyday life. Even in this world however, Mono-1 is quite the oddity as the newest model of Robot. Although her intelligence is at the level of a child, her creator designed her to grow through observation, and leaves her in the care of his son, Morohito, to help her find new experiences to learn from

High school students Kamijou Haruta and Homura Chika are members of a wind instrument club that is on the verge of being shut down. The two are childhood friends and they spend their days practicing hard, while also trying to recruit new members. When a certain incident happens within their school, they work together to solve it.

(Source: ANN)

From Dan of Population GO:

In a world where girls who have turned into an "Eternal Labyrinth" endangers the world, only one person doesn't want to kill them. Arisu Shinnosuke hates society which revels in those who kill the labyrinth diseased girls. Only he strives to find the cure and reverse the disease all in order to save his little sister, who turned.