This will be the second fluffy yaoi manga's post, since I just have too many that I like~ (You can find any series I post on mangago)
XXX Allergy by Hinohara Meguru.
Plot - Growing up in an environment full of all kinds of animals, there’s only one animal that Shouhei loves and that’s rabbits. Because of his love for rabbits, he sometimes helps out in a rabbit specialist shop. And there, he meets Mito Itsuki, his unrequited love. However, he has a secret he has to keep no matter what. Would he be able to keep that secret in order to stay close to the one he loves...?! I LOVED this manga! I'm still so sad that it was just a one-shot. The ending is perfect, even do I had guessed what would happen already xD The art is just, so cute! This is just a perfect one-shot yaoi for any fluff lover!
Kore Wa Koi Ni Fukumare Masu Ka by Susuki Sonoichi
Plot - Popular guy, Hiiragi Tsukasa saves his classmate, Asahina Iori, from an attempted rape. His initial impression of Asahina was that he was a quiet and studious guy. But he’s surprisingly plagued by his problem with attracting guys. So Hiiragi proposes that they pretend to start dating in order to keep the guys off of him. But after promising to protect Asahina from the others, he himself begins to fall for Asahina. This is just one of my all time favourite yaoi's. I'm just ADDICTED to this manga. The plot is PERFECT, the art fits the manga great! and it has a few good funny moments, there's just nothing to complain about!
Okubyoumono Ni I Love You by Sakura Riko
Plot - Due to his scary face, Shougo has been alone since entering university. But unexpected events lead him to become close with Hina, from the same university. Shougo, elated at the fact he's become friends with the cool and kind Hina, finds out that Hina breaks out into hives when people treat him with affection - a "love allergy"?! I just re-read this today, and I still love it~ I just have never read any story like this before, the art is great, and ofcourse I love some delinquent-like characters! Just a great manga to read, definitely unique!