Chuuya and dazai know eachoter for a most of their long live both being respect by the merfolk they alredy figthed together to protect the sea.

They were always arguing with each other so everyone thought they hated each other. So it was a huge surprise when Chuuya started trying to court Dazai to be his mate.

It was a bit akward to watch but in the end they become mates. Actully dazai is swiming around then he saw his mate chuuya swiming towards him