Kono Isekai de, Unmei to Tsugau: Kemono Hito α wa Yasashiu Kedamono

Omega Haru wakes up in an oasis in the desert only to see a beastman appear in front of him. He feels his whole body tremble, and he has no memory of who he is or even his own name. Viano, the alpha leader of the black panther tribe and the one who summoned Haru, speaks gently, telling him he is in a world ruled by beastmen, and that the two of them are destined mates. As Haru learns more about this new world and spends his days with Viano, he feels an irresistible passion well up inside him. However, Haru, who cannot conceive Viano's child no matter how much he wants to, finds himself in a dangerous situation... and remembers. The memories of his former world and the meaning of losing those memories...

(Source: Renta!)