A long time ago, there were two types of angels, the two-winged angels and the single-winged angels. However, heaven is full of double-winged angels, so single-winged angels must find a partner who suits them before they can fly to heaven together - and then fight at the entrance to heaven, the Tianmen, under the supervision of the judge, who will tear off the loser's single wing and transfer it to the winner. What happens to the losers? Will be killed by the judge. After that, the winner will become a member of the heaven as a two-winged angel.