@reu
1. The hyena is described to be a hermaphrodite. To be exact, it's Pseudohermaphroditism. Essentially, it's having the reproductive organs of one sex, but having it look like that of the other. There are 2 other types of hermaphroditism and your snail example being one of them (Simultaneous Hermaphrodite).
2. That's just part of the anthropomorphism. Hyenas don't act anything like any human archetypes.
Also, other female spotted hyenas in this manga wear girl's clothes and fawn over Yena.
@SuperOniichan
So, if I understand you correctly, you want to say that Yena is just a parody of trap characters without any trans context
Never said anything about traps. No, not a parody of trap characters but a parody of a hyena, a hermaphrodite; rather than a trap, Yena is closer to being a futa. The trans aspect was a result of character development and is not meant to parody trans people. Unlike most real trans people, Yena has reason to believe that they were a boy the entire time - their phallic genitalia. Yena was then proven that they were in fact female, and that penis doesn't define one's identity - even then, Yena still identifies themselves as a boy.
and her / his friendship with Hitomi is nothing more than a cute anime female friendship with some gay jokes?
Never said anything about "cute anime female friendship" and "gay jokes". Is it hard to believe that this sort of setup can exist in real life? Well, except for the natural hermaphroditism.
And that Hitomi is typical nice girl with one-sided crush in a love triangle?
Jin and Hitomi like each other.
Hitomi is a nice girl who would befriend girls who had antagonized her friends shortly before (well, it helps that one of them is pretty close to being human). Probably not very typical.