Indifferent to girls, Noboru starts wondering if he might be gay. Noboru consults his open-minded friends and one of them suggest testing it out by asking rumored gay classmate, Yagi. When Noboru nervously approaches Yagi, Yagi mistakes him as a hoop up he was suppose to meet later and kisses him. After Noboru clears up the misunderstanding and explains his true intentions for calling out to Yagi, Yagi agrees to be his sex friend.
Nanase has been secretly in love with his ridiculously stupid best friend Hina for 5 years. When Hina hears that anal sex feels good, he asks Nanase to have sex with him so he can try it out. The two go from best friends to sex friends.
While at a hot spring for their 6 month anniversary, Leo's boyfriend refuses to anything lovey-dovey with him due to being worried about appearances. Infuriated by his boyfriend's lack of affection, Leo decides to find a new partner for the trip. That's when he runs into handsome Ryouta, who came with his girlfriend and the two have an unforgettable one night affair. Leo thought that was the end of it, but then they meet again at Leo's company.
Every weekend Satoya meets his sex friend at 3pm and on the way to his house they buy gelato from gelateria Supernova. Satoya always gets vanilla and his partner always chooses a different flavor. Though Satoya wants to be more than sex friends, the only thing the know about one another is their usernames.
Ch. 1-2,6: Chihaya and Satsuki mutually agree to sleep with one another to console each other over their unrequited loves
Ch. 3-4: Yura, a germaphobe student, is attracted to playboy and politician's son Esaka. When Esaka asks Yura to lend him a pen, it's a signal that they'll have sex
Ch. 5: A man wants to start acting lovey-dovey with his sex friend Shirou, but Shirou doesn't seem interested
Pg. 37-68: Takumi, who's constantly changing girlfriends, realizes Takahiko, Takumi's sex friend since high school, is the only one in his life who never changes
Ch. 6: Kugayama is troubled by his track senpai Ashiya's nonchalant attitude and their ambiguous relationship
Ch. 5: Manga editor Ushio has become sex friends with his masochist boss Ayumu after he thought about quitting his job
Ch. 4-6,0.5: Hayashida is sex friends with his flashy underling Shuuna. But when Shuuna wants to become more, Hayashida becomes afraid and refuses because he hit his past lover.
All Night Long (muno)