Ikisuru Koto Sura Yurusanai

Machida falls in love with Kitayama, a senior who makes her laugh. Machida confesses her feelings to Kitayama, but Kitayama quickly rejects her, telling her that she already has a boyfriend who aspires to be a comedian. Trying to impress Kitayama, Machida becomes a comedian herself, but she is unsuccessful, until one day when she runs into Kitayama again...?

(Source: Shonen Jump Plus, translated)