These are just 2 series that are quite cute and I enjoy reading for fluff~ (You can find any series I post on mangago)
Koishite Daddy by Kitazawa Kyou
Plot - Satou is a salaryman who is raising Rintarou, a toddler, by himself. After an event, he gets closer to his neighbour, Takahashi, a gay university student. Satou begins to get attracted to Takahashi who is fond of children and helps Satou a lot, but he held himself back thinking it would be too imprudent for him since he only got divorced just recently. Yet Rintarou starts throwing tantrums wanting to go to Takahashi's house all the time, and Satou is confused... What is going to happen? Here's a cute and sweet family story! This is just one of the cutest yaoi's for me. I just love yaoi stories with children in it, since there aren't many of them out there. Koishite daddy is just a great series, with cuteness but also some deeper moments. It's a series that will give you lots of different emotions, and it's just such a good read! And if you've enjoyed the story you can read the sequel Love Kids! after~ This is a great must read series.
Neko no Yomeiri by Asa Kusuko
Plot - Once every hundred years a bride is chosen to be sacrificed to god. This time though, Will was chosen. However, the one lying in wait for Will was not a god, but instead a huge savage beast like he had never seen. This beast was a lion named Sachs. He was one hungry lion, so he told the naïve and delicious-looking cat that he was God and took him home… This is a shorter, cuter yaoi story that I enjoy reading once in a while. It's not that known, but I personally really like this story! It's just so cute, funny, and short so it's just a good read if you want some yaoi but don't really want a long story. It's also a fantasy yaoi, which is something I really enjoy reading!