Kare to Koi Nante

Miku just got off the phone with her co-worker and the manager who is also her boyfriend. They made out with each other right in front of her, in broad sight, earlier that day. Saying it'll feel awkward if they saw each other again at the shop, telling her to quit her job. She quits.
Betrayed by a man and without a job. Why is this happening when she did nothing to him? She can't take this anymore and spots a guy sitting across the road. Maybe she'll try hitting on someone handsome for once. And he's okay with it?