Love and Longing... Longing can be expressed as a feeling of wanting or missing something. Say you have a really good expensive video game you want but you can not have, the feeling of wanting the video game and knowing you can not have it would be longing.
As for your story, I can bet you $10 that almost every one is going to have a Romeo and Juliet, because it is one of the most famous Love and Longing stories out there. So I would think outside the box. Say you really like chocolate but you can have it anymore because they don't make it anymore. Or go with the video game theme and say they brand new video game that has come out is only for VR, but you don't have VR, oh!! And say the video game is a sequale to a super good game. Something silly that does not have to do with you walling for the boy/girl/it next door.
