What happened can someone please explain??

Where did it lose you (if you are still wanting an answer)?

Girl loves Soccer Boy, but he can't date and be in soccer, so he asks her to wait and she agrees.
Girl gets lonely not seeing Soccer Boy and gets attention from Yandere who is very attentive. Soccer Boy realizes he's gonna lose girl to Yandere guy, so he asks her to be his secret gf so he can continue to play soccer. Girl starts to avoid Yandere, who is now her stalker and thinks she's being forced to be with Soccer Boy.

Then, the crucial moment, he's Total Whack Yandere and is hurting girl in purifying her, but Soccer Boy comes to save her, and gets stabbed multiple times instead. But he knocks out Yandere Boy and saves girl, but he ends up in the hospital with wounds that are severe enough that his athletic career is over.

Now, all he has is her, so he's become Yandere Boy ...super-possessive and a bit crazy.