Hiroyuki is a 16 year-old boy who is just starting a life of living on his own. He finds a great deal on a huge house for only 10,000 yen a month in rent. Sure the house is a little run down and perhaps even downright spooky, but it's better than nothing...until he meets Milky Way! Milky Way is a Demoness and she has her eyes set on making Hiroyuki her servant!

The Academy City on water, "Rikka". This city, otherwise known as 'Asterisk', was famous for being the world's largest stage for the integrated battle entertainment <Star Wars Festival>. The young boys and girls of the <Starpulse Generation> belonging to the six academies made their wishes with Shining Armaments in their hands, vying for supremacy -- Amagiri Ayato is one of them.

Ayato arrived at Rikka at the invitation of the Student Council President of the Seidoukan Academy, Claudia, and right after that he incurred the wrath of the <Petalblaze Witch> Julis, and ended up having to duel her.

From Yen Press:

One fateful day, Ryousuke Kaga, a typical hopeless romantic and hopelessly perverted high school student, has a chance encounter in the rain with a beautiful girl. After graciously offering both his home for her to dry off in and his help for anything she might need, the mysterious red-eyed beauty thanks him by stabbing Ryousuke in the chest! To further complicate matters, the girl, Lisara Restole, is actually a shinigami–that is, a god of death–and Ryousuke has somehow unwittingly agreed to let her use his “essence” to remain in this world. But instead of shaving years off his life like one might expect of a typical shinigami, Lisara seems more interested in…leeching the letch right out of him?!

From Manga Box:
Satoru Hasegawa, a young real estate agent, lives together with his equally young wife, Aya, and their daughter. Five years into their marriage, he's not particularly dissatisfied with anything, but he's got a secret that he can't tell a soul! Satoru is helpless before Sayaka, an escort, and Eri, his boss at work, and he's been carrying on lively affairs with both of them. But then he meets a woman with the faint aura of first love... This is a romantic suspense story about a man who can't tear his eyes away from that sweet but dangerous trap.

Yachi Haruaki is a high school boy. He has a natural resistance to curses, so his father Honatsu sends him cursed instruments called "Worse" to let him break the curse. One day, Haruaki receives a black cube from Honatsu. That night, he encounters a naked silver-haired girl stealing rice crackers. She is the human form of the black cube, an instrument of torture called "Fear in Cube". Haruaki and the girl 'Fear' fight together against other "Worse" instruments and their owners, using Fear's 32 mechanisms of torture.

From Aerandria Scans:

Suzuhara Mugi is a fifteen-year-old on a mission. She is determined to somehow get onto the campus of Shoukei High School, one of those super super elite high schools. This school is huge and private and has tight security. Mugi is searching for her missing sister--her only remaining family--and she has been led to believe that someone or something on the campus of that school will help her in her search.

Unfortunately, that strict school security is preventing her from getting onto the school grounds. However, her luck changes when she literally runs into Midou-kun, the son of an insanely rich mega-corporation president, and elite person at the school.

Midou is not impressed with Mugi’s sob story about needing to get into the school. He is a very smug and arrogant rich guy. But he can be reasonable, and he eventually strikes up a deal with Mugi--he will get her onto the school grounds in exchange for some labor on her part. She must come to his house and work as a maid! Yeah, this is one of those servant girl stories, but there are a few interesting twists, namely the unexpected way Midou gets Mugi into the school.

Includes oneshot Baby Love in volume 1
Includes oneshot My Fiendly Robot in volume 5

From K.I.S.S.:
Shinichirou would rather spend his life playing games on the internet, but sadly he's a heir to a company. His grandfather deems his current life-style unfit for a heir, so he throws him into a house with eight young and beautiful girls. What's more, within one year he'll have to choose one of them as his bride. What will happen to him now?

Eighth Research is a large biotech company based on advanced research and development of DNA manipulation. Naoya Graphico is on the security team for the company run by his uncle. Naoya has been acknowledged for his high combat skills and is sent on top secret missions regarding Eighth Research interests.

His most recent task has Naoya infiltrating a rival company where a mysterious girl named Celcia has been kidnapped. Naoya's passion for protecting the weak always helps him accomplish missions; he just needs to make sure his libido doesn't get in the way.

Set in a Western Medieval-like place during times of war, Eleonora "Ellen" Viltaria, one of the Vanadis of Zhcted, leads the battle into Brune. There are, in fact, seven Vanadis, named for having each received a powerful weapon from the dragon to individually reign over seven territories. The power of the Vanadis invokes dread and fear from their enemies. An earl in the service of the country of Brune, a young archer by the name of Tigre, experienced the Vanadis's power firsthand after being defeated on the battlefield by Ellen. However, Ellen chose to spare his life after witnessing his skills, but in exchange, he is asked to serve her.

A boy opens a chest at his father's temple, and out pops out a Hanyou, a half demon, half human girl who wishes for nothing more than to avenge the death of her mother and herself. It just so happens that the boy looks just like his ancestor, the one who killed the girl and her mother.

Our protagonist, Ichimura Tamito, is a criminal magnet. Ever since he could remember he had attracted criminals from kidnappers kidnapping him when he was just a newborn, to robbers stealing his toys. He is determined to start a new life and make new friends after moving into a new city but at the start of the day he was bombarded by all sorts of crime. After encountering a knife wielding killer in broad daylight he saves a young girl that coincidentally belongs to the same class as he does. But something seems off about this girl and his new class too. It seems like our protagonist's magnetic pull on crime and criminals is getting stronger as he find out that he belongs to a class of criminals and suspects.

The Japanese title is too long for the associated names so it is included here:
ボウソウガールズテキモウソウレンアイテキステキプロジェクト(B・G・M・R・S・P)

The story of a combined rivalry and friendship dating back to childhood between Beniko and Aoi. They only have one thing is common, and that is that they both love girls. Now they both attend an all-girls academy, and Aoi is more popular with the girls! Even worse, every girls Beniko has a crush on is interested in Aoi. The time for revenge in here!

As a six year old, Rintaro is diagnosed with Henisei Tashu Ijou Syndrome (also known as Hentai Syndrome), a disease that could kill him if he gets sexually aroused. To save him and provide a way for him to live as normal a life as possible, his father teaches him the ways to control his body and mind for ten years in the mountains, with the martial art of the Koei Sougetsu. When he's 16 he chooses to enroll Nangokuren High School, which he assumed to be the biggest all-boys school in the country but is actually the biggest all-girls school that has just gone coed.

On his first day he stumbles upon a large scale battle and learns that the first rule of the school is that it "Abides the Law of Nature" which has turned the campus into a war zone-like environment. Rintaro now sees transferring out as his mission, but will it be that easy now that he's caught the eye of the 3 "Dragons", the bodacious female leaders of the three biggest factions around?

A demon sets out to create an all-girls harem of girls to impregnate and save her species from extinction.

A powerful grand wizard named, “Raim” reappears after a millennium because of a failed experiment. While sets out to regain his lost tower, he meets “are” and “ere” who have been trafficked as slaves... a combination of a weird grand magician who only uses his wits to make money and the cute, lovable brother and sister of the miao tribe! Their endless adventure is beginning to unfold. Editorial staff’s comment Will Raim be able to regain his lost tower?! 

Manhwa you may like:
+ This is another ambitious work of Sung San Young, The Gamer
+ Tower of God
+ The God of High School

As a direct continuation of Mujaki no Rakuen, we see Shouta in even more troublesome and various situations.

As a guy with no real friends, Nishina Tadatora has spent months just observing Ichinomiya Misumi who sits next to him in class. At first glance, Ichinomiya looks like a lonely girl without any special appeal, but only Nishina knows how sensually provocative she can really be. Upon realizing that Nishina is watching her, Ichinomiya begins to interact with him in her own unique way. But unbeknownst to Nishina, Ichinomiya also seems to be harboring a secret...

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.

Senou Natsuru is a normal high school boy. One day he wakes up to find himself turned into a girl. A stuffed tiger "Harakiri Tora" comes to life and tells him to fight as a female psychic fighter "Kämpfer". Having no idea about what's going on, Natsuru is involved in the battles against other "Kämpfer".

Kämpfer is German for fighter.

From Yen Press:

Shouta Yamakawa is in love with manga…and the 2-D girls in it! So when a casually uttered wish to have the lovely, frail Sora Nagihara-his favorite comic heroine-by his side comes true, Shouta can’t believe his eyes! But he quickly learns that while this Sora is just as cute as the one in his comic books, “frail” is the last word that comes to mind for her personality! She’s one bold, brutal babe, and she’s ready to bring the world to its knees for him, her new master?!