From Fantasyshrine:

Kikuchi Yo, a travel agency owner dreams of turning the "Blue Rose", a British noble mansion into a hotel. He enthusiastically approaches Baron Gilfred, owner of the mansion, with his plans. Unbeknownst to him, he's walking into the Baron's trap…! A gorgeous love story between a nobleman and a business owner.

Okuno Ryouko and Saeki are quiet normal students. But only at the surface. At university, they both feel out of place; so, Okuno visits a S&M club after classes. Saeki happens to visit this club as well; rather than participating in the activities like Okuno, he is there to play music. When they both meet there, they seem somewhat attracted to each other. But will this attraction last, when they come to know about each other better? Will love be able to bloom?

The Grand Duke of Sandford and Prince Louis are secret lovers. Although, disheartened by his partner’s cool facade surrounding an exposed love affair with a woman, Duke Sandford is determined to incite the prince as much as the prince does to him… “Unless I can possess you as mine alone, my prince, I’ll never stop!” What would be the outcome of their passionate struggle in this forbidden fight for love?

From Midnight Scans:
Akira, a student of the music department, played the violin only for Ibuki who is her teacher and lover. Akira is entirely devoted to Ibuki while Ibuki's love devours all of Akira to where she has lost the distinction of herself. She believed that Ibuki was her entire world. That was until she met Seike Hayato, a classmate who is the complete opposite of her. An intense, sad love story unfolds on stage in the world of classical music.

Yuki Tachibana, a withdrawn third grader, is convinced that the fourth floor of his school is home to supernatural creatures that few kids (and no adults) can see and he's worried about a recent influx of new, less friendly creatures and about his ability to perceive the true shape of things waning as he gets older. Most of the other kids mock Yuki - they think he's crazy due to his strange pronouncements and peculiar actions - and, aside from the creatures he sees, his only social interactions are with the school's kindly and open-minded caretaker, a new transfer student named Makoto Suzuki who's allocated the desk next to his and an enigmatic boy named IQ who always wears a box over his head.

From FairGame:
A boy named Nishizawa Kazuya is in his second year of middle school. Unlike his younger sister, Rika, he is good at a lot of things and is the fastest runner in school. Parents and others think he is a responsible and hard working child. It seems that he is a perfect and good child but he has a secret that he can't tell anyone.
Every day he enjoys taking a peek at his sister undressing herself.

From Tokyopop: Yen and Jin are brothers in elementary school and successors in the Ragun family craft of defeating evil spirits. In this world, the battle with spirits comes down to a game of guessing your opponent's "name." Once you know the name you gain control over the fight. Both Yen and Jin have secret names only they know ... and must keep them secret or risk death!

From Antisense Scanslations:

Princess May and Prince Kite have been engaged since they were children, and May always believed they would live a happy life together. But when an evil sorceress with a mirror demon (J) and a lust for... well, just about everything, sets her sights on May's kingdom and takes control of her father, everything is put in danger.

Yuuma is summoned back to his home island after the death of his mother and asked to become the next head of the wealthy Nuenaki family. He has certain misgivings though and rejects the offer. However after the current head dies not a day after his arrival, he has no choice but to become involved.

A short story from Pink Gold 2 about pervy little boy and not so smart teacher.

Collection of 6 short stories including:

• Biroudo no Tensoku - The Velvet Foot-bindings
Yuuki's boyfriend Eiichi hits him, leeches off of him, and even whores him out to some of the worst people. But Yuuki still says that he loves Eiichi and refuses to leave him.

Short stories showing some of Oku Hiroya's inspirations before he created his famous masterpiece, Gantz. From Baka-Updates: This series tells us stories about the mangaka's (OKU Hiroya) favorite movies and how it helped and lead to the creation of the manga we all came to know & love - Gantz.

From Gensokyo:

Based on the hit manga by Katsu Aki, "Futari Ecchi for Ladies" takes the story to a new level.
The newlywed story continues, but this time around, the perspective is from Yura, our FE heroine. This tale adds new twists and problems that women encounter.

Sketchbook printed in 2000 featuring character sketches from Matsushita's works including Yami no Matsuei.Includes a reprinted shoujo oneshot: "Inu ga Arukeba" (Walking the Dog): Dog lover Shinri wants to be a guide dog trainer. Unfortunately, dogs seem to hate him and co-worker Iruka never lets him forget it. But things change for the better with the arrival of new dog Wakame.

Kyotaro is just an ordinary guy trying to lead an ordinary high school life, despite the fact that he is the son of a yakuza boss. Then comes Kumiko, his half-sister he's never met before, who's looking for a man with a centipede tattoo who killed her loved ones in the past. Will Kumiko and Kyotaro be able to manage their family business? Will Kumiko ever find and take revenge on the man with the centipede tattoo? And will they be able to control their sexual urges for each other?

In the Under Grand Hotel (2013) series:

V.1 - Kiss & Kill
30 meters underground, a prison where escape is impossible; the United States penitentiary, The Underground Hotel. Only the people who enjoy living in this place, a life cut off from the sun, call it by another name: The Under Grand Hotel. Absorbed in pleasure-seeking sex, the shut-call, Erie (leader of the prisoners) isn't watching the men he's raping each night, but rather one man alone. Norman.

Norman, who keeps trying to harm himself as a result of trauma, the kind doctor who cares for him, Van, and Erie, who's falling into a brutal love that's more akin to hatred. What will happen when these various feelings are made to intertwine into a closed-off world? From storyteller Sadahiro Mika, the long-awaited, mature love story of the Under Grand Hotel begins!

V.2 - Last Dinner
Erie is send to level 4 of UGH and reunites with an old acquaintance.

From Project H:
Sakura Keita, a university student, is in dire straits when he drops a graph critical to passing his class. However, he is rescued by his fellow student, Kurimiya Honoka, who manages to recover it for him. The two hit it off immediately, but will Keita really be able to hold on to his dream girl?

From Kotonoha:

Penned by Masaya Hokazono (Inugami, Watashi wa ai) and illustrated by Court Betten (Prince Standard, Harukaze - Bitterpop), Girlfriend features charming and sexy short stories involving romantic relationships between high-schoolers in contemporary Japan.

Love can be obsessive. Like wanting to rip the wings off a butterfly. Chouko has been in love with Taichiro for a long time. Taichiro and Chouko have known each other since childhood. At one point, Taichiro became very candid and told Chouko that he hated her so much that he wanted to kill her. Even so, Chouko's desire toward him never really changed. One day, a senior in her athletics club confessed to her. Filled with burning jealousy, Taichiro also confessed to Chouko. Their insecure, but very obsessive love begins.

An extra prequel can be found inside of Yoru Koi.

A young man, interested in doing research on urban regeneration to help repair his dystopian sci-fi future, comes to work for the genius Doctor Ginkaku, only to find he's retired from the the country's research institution and taken up... super-elaborate sex toy development? What's more, he needs a guinea pig.