From Impossibility:

Yoshida Miake is a charismatic first year high school student who is in love with her best friend whom she has known all of her life. The only problem is the fact that he has no interest in her whatsoever. Heartbroken, she finds comfort from "Mr. Black" and slowly begins to develop feelings for him. But how can she develop a relationship with a person who exchanges kisses for lunch?

From Fantasyshrine:

Love Alone Won't Do:
High school teacher, Umehara Akio, drew a problem child, Hataoka Kei, out of his home and back to school. Years later, Umehara got transferred to a new high school and met Kei again, who’s working as a delivery boy for a florist shop. Seeing his former student grew into a super good-looking college student, Umehara couldn’t help feeling proud. What he didn’t realize was Kei’s true colors… a pervert who molests his drunken, unsuspecting Umehara-sensei!!

From Midnight Scans:

I'm always into trouble since you’re impertinent, a bit perverted but cute.
My mind is driving me mad by being attracted to a handsome youth who is 4 years younger than me!
Please teach me!!

On the hinge of recession, Tamako joins a household chores company, "Smile Maid". Having an affair will make her lose her job. Uehara is her next job place, and its only son, Yuu-kun tells her that he knows how to cover the affair.
The partner who will evaluate her works is a high school student who always makes Tamako’s heart skip a beat!!

From fictiondb:

WANTED: MARRIAGE-MINDED MEN

Addy Edson was looking for a husband, and she knew just the guy to help her with her search. But what she hadn't expected were the warm, sensuous "practice kisses" that her childhood friend Joe Barrington was bent on giving her--or the way they made her feel ....

Joe was more than happy to help Addy find a groom, especially since it meant the redheaded beauty would be practicing her sexy charms on him! But how could he convince her that a lifetime of happiness--and nighttimes of passion--could be found in his arms?

Naoki is a total fan of the famous and hot duo CROSS. Fate gives him a chance to meet his favorite singer and seems to be deeply in love with him...but his co-worker and friend is in love with Naoki so...things are quite frustrating for all of them...
by kanharu

Kou and his lover Ao have been together for years, but that doesn't stop Kou from cheating on his lover whenever he's had a bit too much to drink. Ao, deeply in love and infinitely forgiving, always takes him back... but for how long?

Tada Mikuni is totally Kou's type... and it doesn't hurt that he's an amazing chef! But when a case of mistaken identity lands them in the sack for a one-night stand, the two of them find out they hate just about everything about each other and never want to see each other again. Unfortunately, they're forced together again when Mikuni agrees to stand in as the chef on a TV show for Kou's agency.

Meanwhile, Ao knows something that neither of them realizes: it seems they've met before...

Micah, a cut throat American businessman, is intent on taking over a floundering Japanese hotel chain and whipping it into shape. All that currently stands in his way is its clumsy yet endearing president, Yuki. Will this hostile takeover end up being a vehicle for love?

1-2) Dripping of Love
Maya and Narusawa, college students at the same university, start sleeping together in what was supposed to be a purely physical relationship. Maya, however, starts to fall deeper into the relationship and has started to want more. Will real love mess up the relationship they have now? The bittersweet story of two people troubled by love.

3) The Distance That Your Voice Touches
Miyakawa's upstairs neighbor Tsukasa is always dropping things onto his balcony, and of course Miyakawa has to return them, only to be fed dinner and sexually harassed! It's getting to be too much for the poor college student.

4) I Want to Embrace
High school student Takase is unwittingly drawn to cheerful energetic Sora. But as his interest and naturally protective feelings toward his friend become something deeper and more dangerous, Takase begins to pull away from Sora.

5) Shake
Kikusui is a waiter in a cafe with primarily female clientele, but lately a handsome man in a black suit has been coming around. Miyamamo has no sense of personal space and a crush on Kikisui.

Extra) Voice of Answer to You
Maya and Narusawa.

Okami and Katsuki have been leading a very romantic life, however, two months into their relationship, Okami had to leave on a business trip. Unbeknownst to him, he left his lover Tarou within the grasp of a sly and cunning man who will resort to even the lowest methods to steal Katsuki away.

Collection of one-shots. (Twoshot story + 6 oneshots) 1) Micky House 01 2) Micky House 02 3) 4) Piyua 5) 6) Me.Ba.E- The new laid back teacher bothers prim and proper teacher Morishita. 7) One Way Ticket of Love (Koi no Katamichi Kitsubu)- New worker goes a business trip with his super cool sempai. 8) Karachi Yuto Usagi Chin

A father and son love each other dearly. But when Emily, a girl from Kazui's past, visits them in Japan, their relationship starts to crumble under the threat of their own thoughts. . .

There is also another one by the same name scanlated by nodeadline by the same author but a whole different story.
Basically one doctor is in love with kazui (not sure if it's the same one from nakama version,) and another dr is in love with him, it's quite a sad and tragic story, but its a good one.

One evening while hanging out, Oku confesses to his friend and neighbor, Kanbayashi, that he is not attracted to women at all and thinks that he might be gay. One thing leads to another, and the two find themselves between the sheets sharing a night of passion. From that day on, though, the pair act as if nothing at all happened. Kan goes on to date a string of women while Oku begins seeing several different men. Three years on, things come to a head during Christmas break, with secrets laid bare between them. Where will things go from there? Two university students explore love, sexuality and friendship in this gentle coming of age tale.

• Koi no Chime
If you could hear what other people's heart are saying, what is it that you want to hear the most?

Collection of short stories: • Koi ni Ochita Oujisama (The Prince Who Fell In Love) "Just thinking about it makes me want to cry. Do you know the kind of love I'm talking about?" Shiho lives next door to a prince. Toshiki-sama is the heir of a Noh music master. They shouldn't have been anything more than childhood friends, but... - ShoujoMagic • Cinderella no Tegami (Cindrella's Letter) • Busu (The Ugly One) • Iroha ni Hoheto • Pizzicato

1) Addicted to Love After School
When his student moves in next door a sensei begins to feel his work and personal life getting mixed up, especially when the paper thin walls let the sensei hear his student's solo nighttime activities.

2) Addicted to Love After School 2
One day, while alone in the student's apartment, the teacher finds a bag full of sex toys. Their relationshp becomes strained as the teacher keeps wondering when the student will be using them in their love-making.

3) Waiting for Your Kiss After School
The drunken sensei accidentally injures his lover/student's private area and is forced into celibacy.

4) Beast of Love
After his parent's death high school student Setsu is raised by his father's twin brother, Ryouichi. Even though Ryouichi is cold, Setsu can't help but cling to him.

5) As Pushy as It Gets
Kazuki runs a convenience shop, and often has to ask his younger step-brother Ryouta to help out as a "pretend lover" for their female clients. Ryouta doesn't work for free however, and Kazuki must pay the price.

6) While Your're Still Out of Uncontrol
Ryouta is requested so often by lady clients he thinks nothing of it. But when a male customer wants to spend time with Kazuki, is Ryouta being cautious or unreasonably jealous?

7) Wonderland in Bed
When Ryouta breaks an arm and leg Kazuki's work load doubles. Plus, Ryouta demands constant attention and care. Kazuki already spoils Ryouta, how much more can the sadistic younger brother want?

8) Newborn Love
Kazuki plans a surprise birthday celebration for Ryouta, but why is this birthday so special?

After Kazui rejects Rai's love, Rai loses himself in sin and hardcore partying. But when his room mate, Mamiya, finds him and tries to make him snap out of it by dragging him home, Rai does the unthinkable to Mamiya in a fit of rage and despair. Having lived a lifestyle doing whatever he wants with no remorse, Rai is suddenly surprised to feel guilt in the aftermath of his night with Mamiya and does his best to apologize. It is only after Mamiya agrees to live with him again that Rai realizes he has growing feelings for the boy. But, Mamiya can't forget what Rai did to him. There is also the problem of Mamiya's unrequited feelings for his best friend Kei. Can Rai convince Mamiya to forgive him, to let go of the feelings for Kei and become Rai's lover?

From Liquid Passion: 1) Do you like cat ears like these? Midori and Satoshi are students at Kuromori Academy, a magic school. They've been together since childhood, and when Satoshi decided to study magic, Midori followed him even though he doesn't really like magic. When Midori casts a forbidden spell his punishment is to have cat ears for a week. Will Satoshi also break the rules so that he too can have cat ears? 2) Medicine Time Souta and Jin also attend Kuromori Academy, the magic school. A love potion goes awry between roomates and there is much misunderstanding (and of course some hot scenes!). Will Souta and Jin be able to have a happy ending? 3-5) Light Blue Triangle Sei and Shuu are childhood friends. One day Sei confesses to Shuu on the steps of a pedestrian bridge, in which Shuu reciprocates his feelings. Due to the shock of the event, Sei tumbles down the stairs and ends up with a broken leg and doesn't remember confessing. This sets off a chain reaction when Shuu is torn about telling Sei the truth of their love confession due to his little brother Kengo also being in love with Sei. Will Shuu tell Sei the truth despite hurting his brother or keep quiet?

From Fantasyshrine: Ryuzaki is an aloof high school student who likes to seclude himself in the infirmary. This, however, teases the stubborn school doctor, Wataru, to seek out other men to quench his lust—!? Or is this love? They both wonder as they desperately fight with their morals. To do or not to do?

It's about two guys who are working in the same convenience store, and one of them seems to be strangely attracted to the other.

(taken from the Evil Empire)

A bunch of cute little stories about the mangaka and her pet ferret.

A high school teacher, Shirai Narumi, can't forget about his high school love who died in an accident. Unexpectedly, at the beginning of a new school year a student, who looks just like his dead love appears...