In a world where humans co-exist with Juujin (literally: "beastmen"), genetically mutated animals that have remarkably human-like features with the exceptions of extremities such as tails and ears, Juujin are...

From MangaHelpers: Hida Kizuna possesses the HHG (Heart Hybrid Gear) ability, but it is not strong enough to make him particularly important. His older sister calls him to transfer to a strategic defense...