Even death will not tear us apart

In the land where the humans live there is always this one day where beings in the underworld visits the human world and crosses the underworld gates to get offer for the dark lord of the underworld. A guy 23-year old guy named Shintaki Yuuta and her wife Shinda were living peacefully in the world of humans, Shinda was chosen to be the sacrifice for the dark lord and his wife as well. As Shinda was kidnapped, Yuuta was killed. As he woke up he didn't realized that he was revived by a being called devil that is named Shi. He became it's servant for one reason, he wants to take her wife back from the underworld. What will he do to retake her wife from the dark lord?