"Animal Jungle" 1 volume-complete by Nana Shiiba
Sumi's mom decides to have a trial family with her boyfriend who has three sons. The art is beautiful but I feel like the cover is way cuter than it is. Too bad it's only a oneshot but on a bright side, there's three more in the collection which are not reverse harem. But I'm not too sure since I'm only up to second only. I want to read third and fourth stories and the reverse Animal Jungle!