Just read volume 1 of Petshop of Horrors in Tokyo and this came to mind.
It's very short, sorry
The shop was quiet and D wondered how much longer it would be before the door would open and a loud, brash man would storm in, throwing around his suspicions of child smuggling around the room between sips of black tea. He wondered how many times it would be said before he would rise to the bait; how many dreams he would have of a certain annoying, blonde detective that night.
The door swung open and D turned, a "Hello, Detective," ready on his tongue before reality settled in.
This one wasn't blonde, wasn't a detective, and even wore glasses. He didn't bring pastries when he opened the door, nor did he leave a child for him to look after while he was off at work.
But he did barge in, uninvited, day after day, drinking his tea and bombarding him with his questions and suspicions.
Taizuu wasn't his dear detective, but he was close enough for now.