Kyouichi's indecisive character has led him to repeatedly commit the foolish mistake of adultery. One day, Imagase, a college classmate he hasn't seen since graduation, shows up as the private detective hired by his wife to investigate his infidelity. Imagase, however, proposes a deal. He won't tell Kyouichi's wife about his affairs, but, for compensation, he makes an unbelievable demand: "I want your body in exchange..."

In the second edition, there is an extra chapter.

From ShoujoMagic:
A collection of short shounen-ai stories by Mizushiro Setona, all connected by the theme of plantlife.
[STORY 01] (English Title) Breakfast (Japanese Title) ブレックファスト (Romaji Title) Burekkufasuto: The tale of a boy who displays the symptoms of man-eating syndrome.
[STORY 02] (English Title) The Tale of the Ring (Japanese Title) 指輪物語 (Romaji Title) Yubiwa Monogatari: The tale of two boys who are dating each other and mutually hiding the fact that both are dating their teacher, who frets because a ring has been lost.
[STORY 03] (Japanese Title) Honey β: The tale of a flower that blooms by inhaling memories. But even if our memories are taken from us, some precious things are never forgotten. "I don't fear losing my memory if I can feel this way again tomorrow..."
[STORY 04] (English Title) Undying Illness (Japanese Title) フジノヤマイ (Romaji Title) Fuji no Yamai See "Mister Mermaid," story 2.
[STORY 05] (English Title) Aconite (Japanese Title) トリカブト (Romaji Title) Torikabuto

Three childhood friends (men) were lamenting about their unhappy lives when a strange beauty with the power to stop time appeared. She introduced herself as an agent of an organization called "Society", and invited them to join a game: after 300 days, the most unhappy one would have all his wishes fulfilled. Who was this girl, and what would become of these three men?...

1) Futari no Tame ni Sekai wa Aru no (2 chapters and an extra) Asukagawa Chiharu is student body president of Ushitora High. Kisaragi Kyou is student body president of Ushitora's rival school, Bishin Academy. That naturally makes Chiharu and Kyou bitter rivals as well, but the relationship they hesitate to flaunt in front of the public eye is one of... lovers! They even have sex at hotels and are an average (!?) couple!!

See "Soko wa Nemuri no Mori," story 02 : "The Star Knows Everything", for a side story of this manga.

2) Valentine Cinema

3) The Queen's Favorite

From Miista MangaFox:

"Sensei, is this a boy or a girl?"
"Do you want to know?"

Ichijo Mashiro and fellow classmates are enlisted in a mysterious weekly class that takes the form of a shared nightmare. Like most teenagers, Mashiro has a secret.. he's neither fully male nor female!

So far, Mashiro's been able to live life as a boy, but all this changes when he's informed of a new class he 'must' partake in order to graduate from his elite preparatory school. To pass, he must find the key and the one way to find it is to enter into a nightmare world, where his body and soul are put at the mercy of the worst kind of enemies -- other school students, who are battling to find the key.

From renowned author Mizushiro Setona, comes a riveting epic mystery that lies between the students, that will have you engrossed from one page to the next. Happiness, sadness, blood and tears will all be shown, but which one leads to an ending? Take the next step into the world of After School Nightmare!

Kyouichi is now divorced from his wife and carrying on a tenuous, homosexual relationship with Imagase. He has even become accustomed to having sex with Imagase every day. However, when Tamaki, a young co-worker with a crush on Kyouichi, appears on the scene, it might be the beginning of the end for Kyouichi and Imagase.
(Source: presencedear)

Consists of three oneshots:

1) Soko wa Nemuri no Mori -
Yui has stopped growing because of something that happened when she was 12 years old. One day, 18-year-old Yuri found a young man with amnesia near the hidden cottage she lives in, and brought him home. Yui named the man "Pochi" because he cannot even remember his name, and she treats him as her pet...!! This is another story from Setona World that will shake your heart and soul!!

2) The Stars Knows Everything -
Futari no Tame ni Sekai wa Aru no extra.

3) Climb the Stairs of Cinderella.

MISTER MERMAID: On a full moon night, Subaru - a merman - coincidentally saved a man who sank into the ocean. After that, in order to see that man again, Subaru traded off his tail for a pair of legs and came to the surface to find Tatsuki - the man's name. Despite of his throbbing feet and his lost voice, Subaru was happy to be able to stay by Tatsuki's side. However, his happiness soon faded away when he found out the reason why Tatsuki was at the bottom of the ocean that day.

FUJI NO YAMAI (side story): Byakuya had an incurable undying illness, which means he couldn't die. Gin, his best friend, made a promise that he would take care of Byakuya until death and the promise had been kept for 16 generations. However, Gin the Sixteenth had no intention of making babies for the next generation; instead, he kept his promise with Byakuya in a way that none of the previous Gins had done.

Sakurai Ichiko is a 29-year-old woman whose head contains council members (each with differing personalities) that dictate her every thought and decision. While waiting at the train station one day, she encounters Saotome, a man whom she met and made short conversation with at a drinking party with friends. Although she’s interested in him, being a much a older woman, Ichiko hesitates over whether or not she should approach him, causing a wave of uproar between her intracranial council members.
(Source: Asian Girls on Mopeds)

A low-price, high-quality apartment in the metropolitan area of Tokyo is nothing short of a miracle! It exists, but there's a catch -- tenants must be good-looking and pass an interview by the landlord!? This is a love comedy about what happens when beautiful people are all gathered under one roof!
credit: Shoujomagic.net