Official English Translation

From Shinmakoku Scanlations :

Volume 1:

Kitagawa Ryouno is the company's most popular hottie, and the ace of the Sales Department. But he has a secret he can't tell anyone. He's a coward, whose face turns red from any unexpected turn of events.
Therefore, from the day he noticed that he would calm down in front of his strict and awkward senior Natsume, the hope of Development Department, he became attached to him. On the other hand, Natsume has his secret, too. He's gay and has his eyes set on Kitagawa, ever since he joined the company... 4 years ago.

Volume 2:

Tomita, a straight office worker who never takes love seriously, has sex with Saito, a bar owner who is unconscious of his loneliness. The result is... perfection. They continue to be sex partners, until one day, Tomita begins to understand his feelings.
Kitagawa and Natsume, who are supposed to love each other and having sex already, claim that they're not dating yet! What is happening?!
The second book takes these 4 hunks on a rollercoaster "love story"!

Volume 3:

The shy office worker, Kitagawa, has continued his secret relationship with his senpai, the cool guy Natsume, in the office. During a trip, Natsume runs into his former colleague and ex-boyfriend, making Kitagawa unhappy. Natsume, who is forced to introduce his new boyfriend to his ex-boyfriend, asks his friend Tomita for help. What is going to happen to these two lovers now that they can’t be honest to each other?!

Volume 4:

Tomita has been living with the barman, Saito, for a while. Despite the difference in their lifestyles, the two are leading a sweet and calm daily life. However, there is one thing that Tomita cannot get off of his chest; How Saito had agreed to act as his best friend’s lover. Ultimately, feeling depressed by himself, Tomita decides to go drinking with his kouhai, Tahara. Drowning in his own thoughts and looking for a way to catch Saito off guard, Tomita fails to notice that Tahara harbors a crush on him.

Volume 5:

Saitou Atsushi’s bar has been thriving and he’s living a very busy life.
Saitou’s lover, Tomita Megumu, is living with him. Saitou knew Tomita would go off somewhere if he left him alone for too long, so he intended to make more time for Tomita by hiring Sakamoto, a taciturn young man, to work part-time in the bar.
Two weeks into working, Sakamoto sometimes showed an attitude as if he was judging Saitou. While Saitou was concerned about this, Sakamoto accepted the invitation of a regular customer and got dead drunk. Having no other choice, Saitou brought him to his home, and when Sakamoto woke up, he flew into a rage against Tomita…?!
Saitou’s past is gradually revealed, and on the other hand, the nature of his relationship with Tomita is also changing…