Based off the popular Japanese PSP game, Photo Kano (or Picture Girlfriend) is about a boy, his interest in photography, and the harem that grows out of it.

From Lezhin:
A UFC hopeful, Kang Doo, gets banned from competition and finds a job as a security guard in the luxurious mansion by the name of Lady Garden; a mansion only allowed to the hottest women. As beautiful as these ladies are, various dangers lurk, and it's Kang Doo's job to protect these lovely women. Oh yeah, and saving women in need always comes with a hefty reward!

From Wasuretai:

For her birthday present, she wishes she could be an ordinary girl. She commutes to Rose Academy in Usuyami Town. She is Little, a beautiful 114-year-old vampire. Her brother Radou watches her, there's a werewolf servant Inukai, and the magical boy Shinji. The ghost that threatens Little's school life has appeared.

Adapted from the otome game: Princess Nightmare

There are some days when it'd be better to just stay in bed... so says Kazuma, an apprentice demon-hunter, on the day when he finds a strange creature in the forest. It's not a bloodthirsty monster, but a young half-human, half-dog girl. Just what type of creature is she? And why does Kazuma sees her at his school right after escaping from the encounter?

Story 1: Renai Joujou
Tsubasa, a normal teenage girl, promises to her dying grandfather that she'd fufill his last wish. However, it turns out that she must marry the heir of a tea ceremony school due to her grandfather's promise? What?! But, there are two heirs, so she must decide who to marry, or if to just run away from her problem.

Story 2: Ouji Sama no Himitsu (The Prince's Secret)
Yukasato happens to witness her school's prince, Matsunaga-senpai, rejecting a confession from a girl, and then freaking out by himself afterwards. Yukasato offers to be his girlfriend to help 'rehabilitate' him of his fear of girls...

Story 3: Rabu✩STAR (Love✩Star)
Ito and Kaho are childhood friends, Ito being the tyrant who bosses Kaho around, and Kaho complying (mostly because his mom asked her to). Ito is a star, but Kaho doesn't see him that way until he drags her along to a photo shoot of his...

Story 4: Chuttoshite Purisu (Kiss Me - Please!!)
Hinata and Jun have been dating for three months, but haven't kissed yet... Hinata discovers that Jun faints whenever he gets close to kiss Hinata!

In the Renai Chuudokuteki Senjutsushi series: 1. Senjutsushi wa Kujikenai - Renai Chuudokuteki Senjutsushi 2. Senjutsushi wa Koi ni Oboreru 3. Senjutsushi wa Netsuai Sareru 4. Senjutsushi to Majin no Shiro 5. Senjutsushi to Fukushuu no Koto 6. Senjutsushi to Saiyaku no Tsubo (1) 7. Senjutsushi to Saiyaku no Tsubo (2) In a certain time, in a certain land, there was a beautiful magician with long, trailing silver hair. His name was Liu Li Xian, a man whose beauty was so great and his magic so powerful, others believed him to be not of this world. However! He had a certain "illness." Which was that he really, really, REALLY liked pretty men. He found them IRRESISTIBLE! Liu Li Xian's grand adventure in seeking out prospective lovers begins!

Rewrite is set in the fictional city Kazamatsuri where treeplanting and afforestation have caused the city to become overgrown with trees and flowers in much the same way that other cities are filled by buildings. However, while most of the city appears to be rural, there are many traditional city elements as well. While set in a modern setting, the city also gives off a strange sense of nostalgia. The basis of the story is set in a high school setting.

From the back cover via Manga Abyss:

"My inheritance is a company that rents out magic users...what!?"

The extremely scared Iba Itsuki receives his inheritance left to him by his missing father: the Magic User Rental Company Astral. The magic users are rented out to customers to solve problems as requested.

How will Itsuki deal with the fate of being president when he's never studied mage-craft!?

Thirteen years ago a disaster occurred. Out of nowhere, a meteorite fell from the sky, and that's when everything started. First of all, there is said to be numerous people who vanished when the meteorite fell. Afterwards, according to certain reports, this was known as "spirited away".

At the same time, strange things happened. The sky filled with clouds, and a red mist shrouded the streets. And those terrible monsters had started to appear. A monster, in other words, a slave beast, one who has sold his soul to the evil king.

However, we must not despair, they have returned from the depths of the red hell, and in order to defeat the impending disaster they carry with them a gift in their hands.

"They have returned, the ones who posses the flash have returned to tear apart the fear."

A collections of one-shots that take place within the setting of the Heart no Kuni no Alice movie.

From Aerandria Scans:

"You've always belonged to me since long ago."
In order to get revenge against the enemy nation, who destroyed her own country, Hina decided to become their crown princess... However, she cannot help being attracted to Ashiru, who's supposed to be her enemy...

From Operation Boredom:

High school Student Kinugawa Kenichi is one of the members of the class committee and also the boyfriend of the super cute Ooumi Chiyako. However, one day, a new student, Kuwabatake Aya, transfers to their school, and demands that Kenichi be her boyfriend...?! Who exactly is this girl, and how does she know Kenichi?

Sidestory of Seitokai no Ichizon.

Hekiyou Private Academy's student council members are decided through what basically is a popularity contest. Since good looking girls are admired by both sexes, unlike boys, the student council room became known as paradise. As the pillar of the student council, Sugisaki Ken seeks to create his own bishoujo harem due to his love of girls.

Haruhiko can't stand his tyrannical father, so he leaves home. The life of a super-rich high school student is difficult. By relying on his relatives, he ended up with a large debt... Even with his classmate Yoriko and his maid Nanako helping him out, things just keep happening in his unfamiliar economic lifestyle. It's a promise-filled, high tension, romantic comedy!

Mina, a Lieutenant of the Space-Time Vanguard Unit arrives from the distant future to interrupt Ichikawa's peaceful life with some upsetting news of how the world would end-up if he continues to pursue his affection about his little sister. The sound of the grim news doesn't seem though to deter Ichikawa resulting in Mina having to take any and every possible action to convince and if necessary seduce him!

Souma Kenichi is in a bit of a pickle. A group of thugs has cornered him on the side of the road and seem very intent on his life. Desperately fighting them off with the longsword he can summon at will, he is saved when a famous teacher of the Miyazaki School and his student intervene on Souma's behalf.Confused but grateful, Souma learns that the sword he wields is called a "shinbuki", or true weapon. Stronger than any steel blade, a shinbuki is created by channeling inner energy into your surroundings and materializing it into a weapon. Normally, learning to wield these supernatural weapons takes years of training under a master. However, a coveted few like Souma are born with the ability to wield shinbuki at birth, and master its use at a startling rate. These rare prodigies are called "Tensaiji".Hunted by a mysterious organization intent on eliminating him before he can become a threat, Souma has little choice but to accept his benefactor's offer of free admission into the Miyazaki School.Note : This manga read from Left to Right

Himoto Sora is a transfer student with a sense of justice and dreams of becoming a knight. Upon arriving at Utopia Gakuen, she learns of a virtual reality-like game played by the male students in which they use girls as weapons in battles for status and treat them as commodities. Seeing one of these girls being abused she steps in and through some sort of error unwittingly becomes the first female participant of the game.

Republished in 2017 in a 3 volume omnibus
1) Shitsurakuen - Hangyaku no Otome no Shou
2) Shitsurakuen - Shinai no Otome no Shou
3) Shitsurakuen - Rakuen no Otome no Shou

This manga tells a story about new Demon Lord Vellmort XIII. Day after day he suffers from boredom, because all Underworld is already conquered by his predecessors, nobody (except maid Sarah) dares to oppose him and he is already sick of luxury food and jollifications with concubines. But some fateful day he has found a solution and together with Sarah has gone to conquer the Ground, populated by humans. Will he succeed in his plan or will he die by the hands of justice?