It's been 500 years since the last female was born. She is now long gone and the EXO clan's numbers are dwindling rapidly. The remaining 12 frantically search for a way to maintain their numbers when they discover that among them is a "bi-gene", a special male wolf with the ability to give birth.

His name is Do Kyungsoo and right now, he is the key to the clan's survival.

It's a good thing that all the other pack members were already in love with him.