note to the reader this is my first review here and it can feature mild spoilers of the lore Emergence is a process to maintain a fixed male to female ratio normally happens in young males At first I didnt know really what was I expecting from Kanojo ni Naru Hi. I was thinking it could be some average ecchi romance manga which uses gender bender/gender swap as main trope for it. But I didnt got any of that This manga was suggested to me by a person on a Portuguese discord server called Geringona where we have this dynamic which we recommend short anime/manga to each other in every 2 Saturdays. And I got this. These are my thoughts: The manga surprised me by the positive. It takes a concept which I kinda understand and tries to make it the lore for the manga. This is because emergence the process that is described on this manga actually happens in our world in some species of fishes and insects/invertebrates Protandrous sequential hermaphroditismhttps://en.wikipedia.org/wiki/SequentialhermaphroditismProtandry. Which it is actually cool a manga which goes around certain elements we find it boring in our Biology classes. Genetics reproductive biology alleles and so on and so on which makes it interesting for those who love Biology and science fiction this is the mangas best selling point. The selling point Im talking about is the way they gently pur the scifi element of the explanation of the gender swap with the romantic slice of life between the two main charcters adding two cups of drama a bit of school life yet with a coming of age theme the manga really got me wanting to read chapters one by one. So two male besties suddenly one emerges as female and the main male characters needs to change his life in order to persude his daily life with newly emerged friend. This quickly turns from a pain in the ass to a lovely romance history with the coming of age element that features some drama to add nature to the relationship which I appreciate. Flexible relationships have their lows and this manga could describe those lows easily a relationship without bad moments would not be realistic which shows even with mild scifi realism really never left the chat. At the end of the manga there were some elements that kinda made me confused all of those could be unecessary. The art was enjoyable the history was decent. I can finally say a Gender Bender manga that isnt ecchi or focus on it I really recommend it only 4 volumes short read I think you will like it. Resuming Kanojo ni Naru Hi is a great gender swap romance manga where the more unrealistic elements somehow are justified in realistic ways and the slice of life elements are enjoyable realistic making the romance and drama present in the manga more human. In fact all the troubles of a are really so put in tought that I could feel this happening in real life if the human species was a protandrous sequential hermaphrodit specie of course. 8/10