A boy wakes up in a strange room and finds a girl passed out with him. They find out they both have weird collars on. The boy has a phone which seems to be connected to the people behind this. They want them to do what?

From MangaHelpers:

There are huge monsters wreaking havoc in Mikagura Kiriwo's city. Building on his father's work, Kiriwo has created a serum that turns him into a giant monster for a short time. He uses this serum to help protect the town from a monster one day--only to find that everyone thinks he's an enemy, too! Everyone at school and in the media hates the "black monster" that he became, due to the massive destruction he did to the town around him. A girl from his class even has to quit school, due to problems caused by the "black monster." Will Kiriwo be able to show that his monster form is really intended to be a savior? [tethysdust]

The world is in a state of isolation. The cause is due to mysterious deep sea entities the navy has dubbed the "Deep Sea Fleet" and they're taking over the seas, isolating all the countries of the world from one another. Refusing to just sit idly by and let the Deep Sea Fleet have its way, all the countries of the world pool their resources to make a new weapon to combat them... a weapon that is comparable in power to that of a battleship... and its name is: The Fleet Girls. Will this new weapon be enough to combat the Deep Sea Fleet? Will the ensign that was just sent to the naval base where the "Fleet Girls" are kept be able to aid in their struggle... Only time will tell as this war against the Deep Sea Fleet begins to unfold.

The "mysterious school comedy" centers on the unusual members of a high-school literary club. Touko Amano, a high-school senior who calls herself the "literary girl" as the club president, is actually a supernatural creature (youkai) that devours stories — she tears pages from books to munch on them. Her club subordinate is Konoha Inoue, a second-year high-school boy who writes stories every day for Amano to eat. He once wrote an award-winning novel, but he wrote it under the penname Miu Inoue so readers thought the author was a mysterious 14-year-old bishoujo novelist. The stress from the novel's fame and its movie and television drama plans turned Inoue into an introverted recluse.

After her normal, happy life shatters, Tokiko and her father move to a small seaside town to live with her grandmother as sixth grade starts. There, the sound of the waves brings back a distant memory from when she visited seven years ago, a memory of almost drowning in the sea and being saved by a merman. Are there really mermaids in that sea? Tokiko adjusts to her new life in the small town as she holds out hope of once more meeting the merman who saved her.

1) Passion Kiss (Yokujou Kisu One night) -
Manatsu has a dream of an incredibly fulfilling kiss. "Who was the boy in my dream? That's the first time a kiss has made my chest ache." That's when Manatsu gets a feeling from her classmate, Morishima-kun -- the same feeling she got from the boy in the dream. Without thinking, and despite the fact she already has a boyfriend, she... (!!!)

2) Second Virgins (Sekando Vaajinzu) -
Kawori is prepped and ready to lose her virginity to Shunsuke... until he penetrates her and it hurts like hell. She wants him to stop, but he can't. They get into a fight and stop talking after that. Then, one and a half years later, Kawori gets coerced into attending a singles party -- and Shunsuke is there! ...As the boyfriend of Kawori's friend Nao? How will Kawori and Shunsuke handle their unresolved feelings?

3) Eternal Summer, Fleeting Summer (Eien no Natsu, Isshun no Natsu) -
The first love letter Takeshita Riho wrote was to Sakurai Touma, the class president she had a crush on from second to sixth grade, but the letter never got sent. ...Until now, when Riho's meddlesome friend mails it out. To Riho's surprise, Touma writes back and responds well to her feelings! He's just as Riho remembers him, and the way he writes makes it sound like those elementary school days were the most important of his life. What Riho doesn't realize is the heart-breaking (and tear-jerking) reason why...

Created and run by animals, Roar Street Journal provides a selection of stories and comics to bring a smile to your everyday life.

Adamsville” is an all ages graphic novel series about two middle school friends who must work together to solve a series of supernatural mysteries in their hometown. What they discover is a vast conspiracy that threatens to destroy everything they know about their lives, town and their future. Now they’re the only one’s who can stop the coming catastrophe.

When a zombie apocalypse hits during the practice of a high school basketball team, it's a whole new life for the coach, Jeff. The world's turned upside down and the girls seem to be handling the changes way better than Jeff, who has troubles adjusting. A close-knit group of friends, the girls are eager to tackle this new world with its challenges!

"Show, don't tell. That's what they told me. "The DaneMen" is a silent comic strip. People all look the same. There are three main flavors: absurd, truthy and grim. Hitchcock said "Drama is life with all the dull bits cut out." Too bad. Life is 99% dull bits. Seems like a waste of bits to me. Chaplin said "Life is a tragedy when seen in close-up, but a comedy in long-shot.” Well..."The DaneMen" has close-ups, long-shots, AND mediums-shots! Take that, Chaplin!"

The story centers around the film crew for Idol Survival, the internationally popular television program where swimsuited idols compete in games. The crew arrives on the same isolated South American island that TerraSave member Claire Redfield is visiting on an investigation.

From AtoZ:
School will bring a fresh start and a way to break free from her seemingly cursed fate. Disaster strikes before she even arrives for her first day at school and a most embarrassing secret is discovered by Chun Hyuk, an aspiring band vocalist who loves only money and music. Can Yu Goon Goon and her best friend, Da-Jung, find a way to shut the mouths of Chun Hyuk and his fellow band members before her high school life is ruined? Da Jung wants to make a deal with the guys but how high a price are the girls willing to pay?

An ugly rumour breaks Rae and Suura apart, will they come back together? How? A completed project, compiled of nine acts, by mangaka Kawachi Yukari.

In this world, every child is born under a god. Some gods are weaker than others. Some gods are stronger than others.

Children born under weaker gods become defunct in society, and cannot attend high school. Instead, they must get jobs after middle school. High school in this world is a place that trains students to use their stronger gods. They have one thing in common: They can grant wishes if the correct price is paid.

Leerang turns back time a day, and pays dearly for it. To reverse his wish, he must attend high school and try to use the powers of his cat god once again.

A long time ago in a galaxy far, far away.
It is a period of civil war. Rebel spaceships, striking from a hidden base, have won their first victory against the evil Galactic Empire. During the battle, Rebel spies managed to steal secret plans to the Empire's ultimate weapon, the DEATH STAR, an armored space station with enough power to destroy an entire planet.
Pursued by the Empire's sinister agents, Princess Leia races home aboard her starship, custodian of the stolen plans that can save her people and restore freedom to the galaxy.

Three boys in junior-high who cross-dress because of differing reasons meet each other through a cross-dressing community website, and decide to meet up in real life. "Parou" started cross-dressing because he wanted to attract a heterosexual boy he liked. "Marika" is transgender and identifies as female. Lastly, "Yui" is an antagonistic boy who adopted the persona of his older sister after her death. In contrast to Parou and Marika, Yui is sorely disappointed at the meeting.

Say “when”. Animals. Animals. Animals. Animals. Animals. Animals. Animals. Animals. Animals. Animals. Animals. Animals … (You can never have too many animals)

From LINE Webtoon:

Sometimes we just can't get out of a ditch; yet we still hope.

After being declared clinically dead, traveling salesman Ed Zamsa tries to go on with his life regardless of his strange condition. As if things weren't hard enough without being dead.

Welcome to the prison-like city of Kowloon. A cluster of conjoined buildings run by gangs. Where the ability of an individual to hope is non-existent. Daniel, Jin, and Ariana are three kids who defy this life sentence. They intend to escape and are willing to go to extreme measures to do so. Since escape on foot is impossible, their quest leads them to the sky.