So I forgot what this was... But the main couple went into a honeymoon trip but something went wrong and they got stranded. The honeymoon trip is meant to make ML a lion beastman (but more beast in structure) and the MC stays the same. They got transported quite far away from their destination (maybe timewise?). They got into a world where beasts evolved into human-like (structurally) beastkins (they're still beast-men) but like at a time where males weren't sporting a human body, only the females have turned into 'humans'. And these males eventually will loose conciousness and become more instinctive eventually... Like they go berserk. Because of some reason I forgot . There they met a transmigrated young man (soul transfer) who's female in terms of that world since he's humanoid. He had no system but he was a medical practitioner(?). At first, this guy can't accept that world's 'culture' of beast and 'human' coupling... But eventually breaks out of that mentality and gets together with a leopard (?) Or was it a panther (?) (It's a sleek furred big feline race but not a tiger). Before leaving, MC lead the transmigrator to figure out the medicine/herbs that'll help the beast-men 'evolve' into humanoid creatures and therefore not go berserk anymore.