From DramaQueen:
Reona is a college student, working hard at the Kaizaki family's Tokyo castle. Ruling over this castle is the young master, Kaizaki-sama. Amidst chores and strict obedience, who would have thought that Kaizaki-sama's discipline of Reona would lead to a fairytale romance?!

Also contains two oneshots:
A Yokohama Story - ch 4
Killing Me Tenderly - ch5

Tsukasa Miyu's life revolved around only one thing--swimming. She gets admitted to Tenkai Academy on a swimming scholarship. However, before the start of high school, she encounters Suzuki Aoi and gets drawn into a world that doesn't involve just swimming anymore...

From Nakama:

Akihiko is the young master of an unprofitable Kimono shop. He has a sexual relationship with his friend Inoue, the son of a president of a bank, in order to get loans to keep the shop afloat. One day though, his servant, Awata, who has harbored a secret crush on Akihiko, stumbles upon their love affair. After confronting Akihiko to stop selling his body to Inoue for money, Akihiko tells Awata to buy him instead. Awata flees the shop and the house in shame. Several years go by and Awata comes back with untold amounts of money that he has earned in the shadowy underworld of crime in order to buy Akihiko. Akihiko is forced to accept Awata with pleasure and indiginity warring within him.

From September Scanlations:

1-3, 6-21) Rutta to Kodama
Ruizaki Takao has a new roommate: transfer student Miyagi Kodama. Ruizaki's a rough guy who gets into fights all the time, but he's gentler around Kodama (who gives him the nickname 'Rutta'), and the two eventually become close friends—until one day, out of the blue, Rutta confesses that he's in love with Kodama…and thus begins their relationship. A beautiful, humorous school-life BL manga detailing the pair's blossoming relationship, with its ups and downs and everything in between.

4-5) Torao and Tatsumi
The 'Western Tiger' Torao and the 'Western Dragon' Tatsumi are not only two of the strongest guys in the city they're also childhood friends.

From Aerandria Scans:

Tezuka Ayane was aiming to become a pianist. She was also working as a part-time home-tutor when she met Narumiya Kou. She found herself falling for him, but there was a difference in their ages and her feelings didn’t seem to be returned. Six years have passed since then and Ayane is a music teacher in an all-girls school. One day, she goes to a jazz-piano audition and meets Kou there..!

1) Ropeman

2) Fistman
Kii-chan, usually the uke, figures it's time for his partner Shiro to see what's it's like... only he plans to use his hand instead!

3) Loveman

For some reason, Chisa's unsociable classmate Jin glares at her every day. After hearing the scary rumours about him being unstoppable, she happens to run into him on the streets. He is bloodstained, and carrying corpses!? Perhaps it was dangerous to have witnessed that!? Moreover, at school the next day, Chisa is shocked when he asks her out! Despite everything that goes against them, are they suited to be together...?

Attonery Tsukihara, is in a relationship with fireman Hino. However, their continually busy lives are making it difficult to spend time with each other. Will Tsukihara's bad habits show their face...? When a junior at the office, unexpectedly comes into the picture. Spells a recipe for disaster, and Hino's senpai is inadvertently attacked.

Yutaka works as a trainer at his father's boxing gym. In a dark alley one day, he runs into Kei, who fights off several thugs. Trying to help a young delinquent get off the street, Yutaka invites Kei to the gym. But Kei is no ordinary delinquent...

In the series:
Vol. 1 - 白い獣の、聞こえぬ声の、見えない温度の、 Shiroi Kemono no, Kikoenu Koe no, Mienai Ondo no,

Vol. 2 - 赤い桎梏の、約束の場所の、望んだ十字架の、Shikkoku no, Yakusoku no Basho no, Nozonda Juujika no,

Story of landscape gardener Ono Hiroshi, 29 years old (187cm) and tax office worker Kumedera Katsuya, 27 years old (154cm).

Kumedera met Ono while he was attending the Free Municipal Tax Consultation. As Ono was totally his type, he called out to him, and after discussing tax matters, he invited him to go out for drinks. After a one-night stand or so they thought, they began dating.
We follow their relationship with aggressive seme Kumedera, who insists that Ono is his "WOMAN", and goes as far as treating him as one, (even though both admitted being gay). On the other hand, we have Ono who can't seem to be able to refuse anything to his dear lover, especially when it comes to sex!!!

Volume 1: Chapters 1-2: Being the notorious school president of Seiryou Academy, Hashizume had control over every student and staff member. But when the transfer student Misonoi appears with his nonchalant and unassuming attitude, Hashizume sees his newest challenge in taming this new toy.

Chapters 3-4: A story about cousins who fall in love.

Chapter 5: Oneshot about professor/student relationship.

The Series Goes Like This:

Volume 1: Seiryou Saikyou Monogatari (Scandalous Seiryo University)

Volume 2: Seiryou Saikyou Monogatari Returns (Return To Scandalous Seiryo University)

Volume 3: Seiryou Saikyou Monogatari Limited (Beyond Scandalous Seiryo University)

Volume 4: Seiryou Saikyou Monogatari - Yano x Ishida Hen
- Serenade

1) Bi no Isu (The Coercion Chair)
Kabu and Nirasawa have a troubled relationship, to say the least. Harsh yakuza lifestyle, torture, and violent sex are everyday occurrences for the volatile couple.

2-3) Anya no Tsubute
Sequel to Bi no Isu

4) Tokage to Choutsugai
Emiri is impotent, thanks to his trauma of being molested by his childhood friend, Fuyu. Years later, Emiri is finally seeking treatment for his condition, but why is Fuyu wearing that white coat?! And why is the nurse's skirt so short?

5) Seiritsu Shinai Asa (The Morning That Will Never Happen)
What will happen years later when senpai and kouhai meet again? Is loving someone that frightening?

The all out story of two guys, the wild and completely unpredictable Hana and the reliable, cool but somewhat naive Ikkun in a cute relationship filled with passionate love and jealousy!

They are cool! They are hot! They are irresistible!
No girl will refuse to share her bed with these Sensei.

1 & 2: Baby, Baby ー A Narcissistic Scriptwriter by Takahashi Yuu (高橋ゆう)
While enjoying a meal with her friends at a restaurant, Miyako expresses her dislike for the famous & handsome scriptwriter Yuuji and calls him a narcissist. Yuuji overhears her and gets really pissed off. Later he encounters Miyako as an employee of the publishing company he has recently signed a contract with.....

3: Higurashi Naku Yuugure Ni ー An Intellectual Librarian by Saionji Michiru
Touno Sensei's wife passed away 3 years ago and since then he had locked up his heart. He wanted to lead the rest of his life in the memories of his wife and so he left his teaching job and diligently started to take care of the library his wife left him. Nene who was once Touno-sensei's student is now a regular at his library. Nene has a hidden dark past due to which she has grown averse to love. Can these two scarred souls find solace in each other?

4: Love & Peach ー A Perverted Doctor by Ashika Nozomu
Izumi is suffering from haemorrhoids. She visits the hospital for treatment but slaps the proctologist Dr. Shuu since she mistakes him to be sexually harassing her. Coincidentally, that evening, Shuu and Izumi meet at karaoke on a group date and things start to get interesting...

5. Sweet Teacher ー A Confident Trainee-Teacher by Earithen
Kiori is currently working as a trainee teacher to obtain a teacher's license without which she won't be able to graduate from the Department of Education. But the problem is that she doesn't really aim to be a teacher and so she slacks off in her duties. Her perverted supervisor offers to help her get all the required credits in return for sexual favours. Helpless Kiori yields to his demands. Can the good-hearted Kazama-kun, another trainee teacher, save Kiori from being taken advantage of?

6. Ai Wo Hore! ー A Cute Homeroom Teacher by Koishikawa Funi
After being betrayed by her first love, Futaba believes that she can't fall in love ever again. She feels herself buried under a huge pile of snow because of the unexpressed feelings that have been accumulating in her heart. Can the cute child-like Horishi-sensei, her new homeroom teacher, melt her frozen heart (and body) ?

From Fantasyshrine:

"There's no way you can run away from me-- I MUST HAVE YOU!" said the super-egotistic ex-host Hisakawa as he carried a bouquet of roses, to the beautiful yet uptight sensei, Shindo Misaki!!

Under the masterful fingers of his pursuer, Misaki was assaulted by a powerful lust, which rendered him defenseless to Hisakawa's advances. Though in truth, it was Misaki's unconscious wanton responses that captured Hisakawa's heart!

Lovely manga anthology on love and sex, plus a bit of humor for female readers. This book features all the stories of female characters falling love with her senior students. Includes 6 works from 6 authors: 1) "Zakuro no Mi wo Abaite" (Opening Pomegranate Fruit) / Mayu Shinjo : Prideful Kotoko is greatly admired at her school, but will that change when ruthless Takahiro backed by a powerful family sets his eyes on her? 2) "Sexy Shiyouyo!" (Let's Do Sexy!) / Yuuka Kousaka 3) "Jun-ai Egoist" (Pure Love Egoist) / Mio Ayukawa 4) "Netsu-ai Byoutou" (Love Fever Hospital Ward) Yuka Murata 5) "Wagamama na Kuchibiru" (Selfish Lips) / Haruko Kurumatani : Yuu gets a job acting in a commercial with popular idol star Kano Itsuki. When Yuu works up her courage to introduce herself, he kisses her! What does she do but punch him. 6) "Double Face -Akogare no Senpai Hen-" (Double Face -Senior Student Version-" ) / Kai Uchuuda

An anthology of 6 stories. 1. With Those Fingers, Those Lips -- A playboy decides to mend his way? 2. Shakuren/Miraculous Love 3. Toge Made Itoshii (Dear Until The Thorns) -- A sweet story of how a girl found love after her ex cheated on her 4. That's What Makes You A Liar -- What's real and what's not? The heroine learns to stand up for herself. 5. Make Love to Me with That Voice -- Erika loves Takashi but sleeps with Touya who has the same voice 6. Love Idiot -- Strong girl becomes an absolute idiot when she falls in love. Luckily, he realizes it and helps her find herself again.

It's 1904. Natsume, the son of a old and prominent family, is cursed with a small, frail body. Because of this, he isn't qualified to enlist in the Japanese forces for the upcoming war with Russia. He is unhappily resigned to becoming a teacher. That is until he meets Daigo, a student. Daigo reminds Natsume that he could inspire and lead just as many future soldiers and leaders of Japan as a teacher, as he could as an officer. Daigo promises to become a great solider under Natsume's tutelage. But unlike Natsume, Daigo isn't in it only for the honor of Japan.

1-2) Student's Request Teacher's Duty
Yahiro sensei is adored by all of his students, especially the girls, but it's male student Koga that Yahiro can't stop thinking about. But as much as they love each other, Yahiro knows that the affections of a teenager can be precarious.

3) Sakase! Takae no Hana
Nozomu's father has recently remarried, and his new step brother is super popular Sudou sempai. Sempai is very affectionate with his new little brother, and Nozomu's trying not to let the attention go to his head.

4) Honey Happy Baby
Yui Tomoya was looking forward to a special date with his older boyfriend Tsukasa, but is thrown off track when he's forced to babysit his niece Ayumi. And why doesn't Tsukasa seem to mind the interruption...

5) Voice Box
High school escort Atsushi gets surprise when his beautiful-voiced client is a journalist looking for a good story. But after a night of gentle passion, the journalist disappears leaving Atsushi wanting more. Will he ever meet his mystery man again?

6) Scandal Kiss
Stuntman Hideto has been dating famous actor Katsuya, a former ladies man for a while now, but his feelings of jealousy at seeing Katsuya with other women are becoming too much to control. Is it really just for work?

7) The View Through the Lens
American photographer and ex-felon Rob Dain picks up young orphan immigrant Tohru one snowy night. Making Tohru his model, he obsessively photographs the teenager, but his one true desire is to see Tohru's aroused face. How far is Dain willing to go to see his dark desires fulfilled?

'MEGA EROS' edition (Enterbrain) have additional story:
8-10) Best Place

Friends, coworkers, lovers, ex-lovers, arranged marriage, lesbian, gay, S&M, cross-dressing, revenge, vampires, classmates... Every story is a peek into the different relationships between different people.

Most of the stories are only 1 chapter long. The last volume features a series of stories centered around a pair of twins.

1. Miyako's Plate

2. Kurosawa's Umbrella

3. Hanna's Flower