Chuuya and dazai are both yokai chuuya is a oni and dazai a kitsune both are over 900 years old.Youkai's have soulmate's that happen's when one youkai soul is interconnected with another's youkai's soul that is the most important relasonship youkai's have. Chuuya and dazai are soulmate's and both know it but they didn't talk about it even knowing they both are soulmate's they aren't really on romantic relationship of course they alredy kiss eachoter.Kitsunes like dazai have a thing called heat or mating season that is when kitsunes want to have babies and are very clingy to their soulmate they get on heat every 50 years or so dazai.Dazai told chuuya was in his mating season and ask chuuya to come to his Room when chuuya got on dazai mansion a servant comes to him

"Chuuya san please go to master dazai room"the servant says to chuuya