I remember reading this in jjwxc, so there is no translation of this, I think. The story is about a freshwater merman who goes to an academy in the deep sea, because he wants to see his mother, who separated from his father and now lives in the sea. When he goes to see his mother, he sees that his mother has had physical changes to a more masculine one, due to the adaptation on the seabed. In the academy, it is seen that the students are of very diverse races of different sea monsters. And the ML is a titan mermaid or something like that, a merman race with a stiff tail. Something very curious about this novel is that sometimes they included notes from historians, who commented a bit on the history between the MC and ML, since it was the first pair between the deep sea merman and the freshwater merman, and they compare it with the relationship between a primitive man and a man of the modern era, which was laughable. Finally, at the end of the novel I remember that the MC could not have a child with the ML, since they are both male, but the god of the sea or something like that, blessed him and in the last chapter it is mentioned that he had to withdraw from the academy due to his pregnancy. Important points: There is nothing of rebirth, transmigration, interstellar ships, etc.