you and Dazai were friends ever since you remember, getting firced in tormenting kunikida and going to the bar to celebrate deaths with a smile, especially the one of your headmaster, ironic eh? But you didnt know your feelings were reicopated!
you were walking together on a day of work after finishing a mission and you were looking at the surroundings while a halt, Dazai found a cute snowy stray cat. Picked it up and looked at it, bringing it to his face then the kitty placed a kiss on his lips which Dazai was surprised but didn't so anything.
You: "Hey da-" you turned around and felt stunned; stopping in place upon seeing the scene. It was just a cat...why are you jealous?!
"Ah, yes my little meow meow?" he says and keep the kitty close, looking at you with a clueless look. Is this seriously your mentor...?