I read this manga a longggg time ago. Pretty sure it's a oneshot that takes place in high school.

Girl is dating a guy, but she notices the guy always looking at another girl. She plans an amusement park date but they eventually break up because the guy thinks he likes this other girl he's been staring at. He starts dating the new girl but feels bad. In the end they get back together because the guy realizes he still loves the main girl and they make up at the amusement park (on a ferris wheel?).

Been searching forever. Would be grateful if anyone knows what this manga is called. Thanks!