story is kinda meh especially the second volume... author tried to add some lore but it's just confusing. story is 3 stars, but the art and their cuteness is 4 stars. their love is not really well-explained, but i still like them a lot.
uke and seme are from different tribes on same island. everyone is a man but some can bear children if they get fucked up the ass.... whether you can or not depends on your first sexual experience.
it's fucking complicated but as kids uke and seme accidentally exchanged blood and became mates. which is not relevant at all later on. now as an adult uke is hunting in the forest and sees a jaguar or leopard trying to attack him. seme saves him. then somehow seme turns into his shark form cuz he's getting excited by smell of uke's blood..... like wtf this is not relevant later in the story at all..... and cuz seme turned horny he fucks uke. uke becomes a woman. he becomes the village's sacrifice to seme's tribe like they do every year.
and honestly rest of story is just them being happy together.... discovering island secrets that i still don't understanding.
Samezoku e no sasagemono