Social Savvy Class 101

A high-teen secret romance unfolds when 'Outsider' (an outsider) becomes the manager of the anonymous community app 'Inssa Time' and learns all the secrets of the entire school and joins a group of super popular kids that he desperately wants to get involved with.
Kang U Bin is a popular kid among the popular kids and a trainee at a large entertainment agency who is admired by the entire school and is seen as perfect by his classmates. He not only has great visuals but is also good at studying. He seems like a born-to-be superstar who exceeds the webtoon's setting, but he is hiding a secret that no one can find out about. U Bin, who has never been suspected, ends up in an awkward situation because of 'Outssa', whose name is even confusing.
(source : mydramalist)