Help me find the manga, please.

I have read this before but I forgot the title, even though I have the titles I have already read on my notes but I forgot to put some tag or comment that is unforgettable. I wanna r-read it in short because I'm reading similar to it. (Moudoku Sugar Syrup) I have tried the search tags that I can think of but, failed.

I remember it like this: It has an age gap, the ml is a shop owner, noodle shop I think. The uke wear mask when he meets his customer to hide his identity when drinking their cum (they need to drink to be alive, they are not a vampire I think but close to it). The work place owner that the uke work in is his not blood related uncle that took care of him. And if I remember correctly (first encounter) when the shop owner (ml) help him when he fainted, uke started to work there part time or any occasion he is free. It's a manga.

Hope it helps... thank you very much in advance.