(Crossover because obsessions go hard) Chuuya and Dazai both met on Isle of the Lost. Chuuya was the son of Hades and Dazai was the son of the mad hatter. (The was a misunderstanding and that's how the madhatter ended up on the aisle) the two met one day and got along well. They began dating and have been for a while now. It's safe to say it's obvious Dazai's dad is the Mad Hatter. As for chuuya who uses any opportunity to use his blue flames he got from his dad Hades