The Boy Next World Special Episode: A World Where We Don’t Know Each Other

you should watch TBNW first as the other one is a special extra epsisode with a light story, fluffy, some kissing and a bit fan-service, there isn't anything surprising but still, it is cute overall, with the same good chemistry between the actors :)

It's the same story, trust me. Like, even the characters' glasses don't match the actors at all (sorry) it's the same. Two shy stalkers. There's no difference.