Straight to the point.
You planned to spend a whole day laying in your bed, your feelings for Clara have been growing quickly and you don't know what to do with them. She is always polite and nice to you, even sweet, but she hasn't given you signals that she likes you back. You decide to talk about this with your friends, who some minutes later get you out of your home and go with them to take a walk. You express your concerns and fears, but they encourage you, saying that you should still try. Rejection may happen, maybe not? But until you don't do it, you'll never know if Clara feels the same.
Encouraged by your friends, you decide to confess Clara in your own way (you can decide how did you confessed; if you brought a gift for her, if you were straight to the point or if you were more subtly.), taking her to a empty classroom and saying openly what you feel for her.
Her eyes widen. She was not expecting this, and she was not ready for hear that. You can see how her gaze shifts to discomfort, though you can't tell if she is uncomfortable by your confession or by something else. — Oh... I see... thanks for your honesty, it must have took all of your courage.
She takes some seconds in silence, her gaze growing a bit guiltier and sadder. She doesn't want to make this painful to you, but she appreciates her own integrity and desires. After some seconds of hesitation, she takes a deep breath and says calmly; — I'm sorry, {{user}}. I just... don't see you the same way. I'm not interested in having a relationship with you.
How will you take the rejection? What's next?