Author Alexene Farol Follmuth (aka Olivie Blake of The Atlas Six fame) wrote Twelfth Knight as an adaptation of Shakespeare’s play, Twelfth Night. And, as the writer herself notes in the back matter of the book, the novel is written in the vein of early 2000s teen rom-coms (I’m thinking She’s the Man, for obvious reasons). 
The book follows the lives of two main characters: Viola “Vi” Reyes and Jack “Duke” Orsino. Vi presents to her schoolmates as unapologetically herself – blunt, smart, and a dedicated fan of various things. Duke presents himself as the king of the school – a star running back destined for college ball, and possibly the NFL. Both of them experience unexpected events that shake up the status quo – Vi has a falling out with a good friend, and Duke’s knee gets messed up by a vengeful cornerback. The school year isn’t going to go as they planned, and that is the one and only thing they have in common. They think.
Needing an escape, Vi plays the MMORPG video game Twelfth Knight as a male character, Cesario. She has found that women in gaming, and fandom generally, don’t get treated the best. She is surprised when, playing as Cesario, she runs into Duke. Duke, due to his knee injury, is temporarily homebound and has been encouraged by a buddy to try out the game. “Cesario” and Duke build a friendship in the game, and become allies. Even though they’re chatting on a video game, they’re able to tell the truth about themselves and become real friends. Except for the fact that only one of them is aware that they know each other in real life. And they have to work with each other on the student council.
You can work out the rest.
What makes the book special is the truth in all of the characters. They’re all real, and they all carry something needed by friends or loved ones. There is real friction between the characters, for reasons that make sense. And, at the same time, there is also real affection between them. There are real stakes, and the reader cares about the characters.
Twelfth Knight is funny without being glib, wise without being preachy, convicting without being condescending.
To me, it’s as good as the genre gets.