What is so special in this story?

The idea of ​​the drama is interesting, I managed to see the first 4 episodes, but, psychologically speaking, I saw an immature love, broken by the selfishness of the main heroine and the masochism of the main hero. Why the Korean public considered love in Nevertheless toxic, and here they feel butterflies in their stomachs, remains a mystery to me. She shows selfishness, expects to receive love without giving more than rarely, and he confuses attachment with love.
The actors are good, nothing more to say.