Rain Prince and Flower Sacrifice

The setting is a country where a myth remains of a prince who defeats a disaster dragon and rescues a sacrificial girl. Five days before her wedding, the "bride" rescues a man named Jiu who has collapsed behind the house. Jiu is injured and appears to be being targeted by someone, so the "bride" proposes a deal to Jiu, asking him to listen to her request in exchange for hiding him. The encounter between the two changes the fate of the country of dragons. (Source: Natalie, translated)