From MangaHelpers:

Nagumo Yumi is an idiotic high school girl, whose post-graduation plan is to go to the US and become president. To her high school friends' amazement, she actually manages to make it to the US during summer vacation. After befriending some elderly veterans, she becomes convinced that joining the Marine Corps is the best way to move her dream forward. The waitress Linda Crawford joins her to sign up at the recruitment center, and she also meets friends among the new recruits, Rita Fernandez and Donna King. Will they have what it takes to become a Marine? [tethysdust]

In Tokyo, suspicious cases are occurring where the victims have all of their blood drained from them.
Mikogami Keiji, a detective who also wants revenge for his lover, killed 10 years ago, pursues the culprit, the “Man with two faces”.
What is the identity of the silver-haired girl who observes him…?

From Manga Updates: A very popular early work from Kinoko Nasu from the Tsukihime & Fate fame, the Kara no Kyoukai universe has meet great success as an animated film adaptation, novels and radio dramas. Kara no Kyoukai depicts a world were the true dark nature of the human being is being reviewed and exposed by shocking and ruthless events, and in the center of it all we have Ryougi Shiki, the true heir to the long lived, wealthy and mysterious Ryougi clan and Kokuto Mikiya, a would be normal high school student if it wouldn't be for his amazing deductive & investigative progress. The moment Kokuto and Shiki meet is the moment that the wheel of fate started to turn, however is this fate moving forward naturally of it's own accord, or is it all being orchestrated from behind the scenes by an enigmatic persona? Only time will tell.

An abused little girl with nothing to live for meets an old man with a nasty personality

It's been one year since Rin moved to Tokyo for high school. He was told by the landlord of his apartment that he didn't have to pay rent if he takes care of the landlord's granddaughter, which he immediately accepted. However, that granddaughter, Mako, ended up being a 20 year old college student who is completely incapable of taking care of herself. Even so, it was love at first sight for Rin, and he's been taking care of her ever since.

Imaizumi is a high school boy who lives alone in his apartment for a reason. He has a secret that he can't tell to anyone. And the secret is that he lives with the top three Gyarus (gals) of his school, Hamasaki, Kurumozaka, and Sasaki. He spends his day playing, talking and getting physical with these Gyarus, all of whom have a quirk or two. Imaizumi-kun is getting more and more addicted to his lazy, naughty and free "youth"...?

Nagisa Ootsuki shed her former self out of shame from failing her highschool entrance exams. On her first day in her new highschool, who does she meet but the girl who made her fail the exam! How does Nagisa deal with these complicated emotions?

Author's twitter: https://twitter.com/sakuragi_ren

This is a world where androids operate virtually indistinguishable from humans. In this world, assistant android Hinageshi has fallen in love with high school novelist Kaede. However, if anyone were to find out, she’ll end up being processed. The debut of a rival, her first friend, a mysterious phone call and the sweetness of youth. A story with many twists and turns!

"Hello fellow citizens. I am Yoshida the half-elf, working for the post office of the Imperial City of Idazig. My job is to deliver letters and documents to wherever you need them to be, whether it be a castle in the sky or the bottom of an abyss." This is a comedy written by the biggest Medieval Ages geek, hitting the fantasy genre from an entirely new angle!

Spring has come. I, Haruto, now fully fledged University student and I can live in apartement alone independently. But my father suddenly send me a "maid" because afraid with my condition. The maid who came to my apartement is a huge pervert with her erotic beavior and dirty mind, and me the adolescent boy always assaulted everyday by her.

In a politically arranged marriage devoid of love, Lily is wed to Theodore, the head of a rival family. Theodore loathes the union, but little does he know that Lily despises her own family as much as he does. Living a quiet life, she counts the days until their inevitable divorce. Then fate intervenes—a sudden accident erases Theodore’s memories of her, transforming his coldness into unexpected affection. Can Lily trust this dramatic shift, or must she guard her heart to avoid future heartbreak?

One random day, a high school girl is suddenly able to see ghosts! She can't run but she tries her best to act like she can't see them at all. The story of a girl with a sixth sense begins!

Killed on the battlefield without glory to his name, Yuseong Dan receives an opportunity to grow stronger with a strange quest and level system. But each quest he’s forced to fight only seems to be getting harder and harder. Can he level up enough to avoid the same miserable ending and become the powerful hero he wishes to be?

Metalia, a world where mechanical creatures called the gears stroll. It was the so-called "machine hunters (collectors)" who hunted those who ruled the earth with mighty power. A boy now descends in Melzam, the largest city in Metaria. His name is Nill. He, with the right arm of the machine, had a secret. This is a story that looks for your fate.

Yamada was hospitalized after breaking both hands, to make things worse, due to a unknown condition he has to ejaculate every three hours. The ward is full of evil nurses. Will Yamada be able to live and be discharged from the hospital?

TLDR: Guy has busted hands, gets sent to hospital for chronic ejaculation, guy gotta get his nuts busted by busty whacko nurses.

Yuichi Shiro is a foolish, narcissistic, and oblivious teenage boy. After a sudden incident his once ordinary life goes through great changes. How will the optimistic self proclaimed genius handle the life he will lead from now on? As well as handle the new acquaintances and enemies it brings with it. Let the story of action, life, romance and stupidity begin. (Original Web Novel: https://www.fictionpress.com/s/3068594/1/Soul-Anomaly). Current cover is actually from the web novel that has a different artist to the manga.

A world where machine civilization has perished and immortal monsters called "Monotsuki" are rampant. Isana, a girl born in a remote village, meets a mechanical person who lost her memories and looks exactly like her sister, who should have disappeared in the ruins she wandered into. Convinced that "My sister is alive," Isana gives the mechanical person the name "Hime" (princess) and together they set out on a journey to find her sister.

The first life. After a tragic accident losing his family and legs, he ends his own life. The second life. He earned fame as the Red Demonic Master in Zhongyuan, but was betrayed by the man he trusted the most. And now comes his third life. In his life back in the modern world, Gang Jinho decides to live a normal life... However, he was too used to the Zhongyuan life to become a normal person! 'I wanted to live peacefully. But you are the ones who started it. I hope you're prepared for this.' In front of the threats of his new life, can Gang Jinho shake off his impulses as the Red Demonic Master and obtain the 'normal life' he desires? The adaptation story of a legendary martial artist in the 21st century!

Fuyuki is a beautiful and cool gal! But there's a secret side of her that she only shows in front of her husband...? A cute love comedy with a gal wife!

Elven girl, "Aria" is an adventurer. A small beast with an adorable face embraces Aria's fruitful chest, she decides to keep it as a pet and names it "Tama". At first sight it's just an average cat, but Aria has yet to notice that Tama is a former Knight and that his identity is not a cat, but a young monster of the strongest class "Behemoth".