Neither of these BL, starring Yoon, are meant to be taken seriously. But where Unforgotten Night reminds of an amateur Wattpad novel with adult themes, YYY goes about it on a wacky manner that’s not unlike old kids shows. Regardless though, if you like Yoon or want a show to turn your brain off to, either of these dramas would be a good fit.
Made by the same director, it has a very similar style of editing, cinematography/lighting and overall atmosphere. Both have animated elements integrated with live-action too, and they even share a part of the OST. Why R U is referenced a lot through YYY, and Porpla is a fan of the series and SaifahZon shipper. Both series have playful, wholesome couples. YYY is at a higher level of 'crack energy' though, but Why R U is also more 'crack' than your average BL series.