it's a lesser known yuri manga
What I remember...
The mc was walking around town thinking that the girl she likes, likes her back, then she sees her with a guy somewhere in a big crowd.
After she saw that, the mc stopped walking and was thinking
"That's right, why did I ever think someone would fall in love with me", (or something along those lines), while drowning in the crowd. While thinking that, the view kind of zooms out and we see her tear up while still smiling.
That's about all I remember...