Vintage 1900 by Hikari_Kaitou (Ao3 ; Tumblr)

Ryuunosuke didn't expect to personally reap many benefits as a result of his role in helping to solve the case at the end of Dai Gyakuten Saiban 2, but he couldn't deny that he was enjoying the tentative friendship that he and Van Zieks were forming in the wake of its conclusion. In an effort to recover from his undue prejudice against the Japanese, Van Zieks asks Ryuunosuke if he would mind teaching him more about his homeland, starting with an aspect that already appeals to him: Japanese wine. Ryuunosuke proposes that they try making some together. Over the course of the five month fermentation period, the two of them get to know each other better on a personal level and come to realize that they might be more compatible than they realized.

beware of DGS2 spoilers

cover by me :)