Whether it's the main meat of the plot or part of its sides, romance has played a part in a lot of anime. There are always ups and downs when it comes to building a relationship, so it's rich ground for adding some extra drama to the story and turning it into an emotional rollercoaster. Like when a potential romance is forbidden. Whether it’s because of society, a curse, or other reasons, anime's wanting lovebirds have a lot going against them.