On a Leash manga summary: From Lezhin: Tensions run high on the battlefield as soldiers fight through death. Bombs rain from the sky and bullets pepper the ground. In battle, beasts screech through the sky and tear through the earth. After the smoke clears, the soldiers return to their human forms weary from battle and numbed by death. But amid the explosions and chaos, a spark of passion ignites. Time will tell whether it can survive the horrors of war, or if it will succumb to it.