Ony, the Senior everyone talks about, and Yeonwoo, the junior who sees him as merely a 'Grandpa'... Their paths keep crossing, much to Yeonwoo's chagrin. Yeonwoo, known for being prickly and blunt, sees through the popular senior's charm. But one night, everything changes. Yeonwoo stumbles upon a heavily drunk Ony, about to be taken advantage of, and steps in to rescue him. Following the incident, Ony, who noticed that Yeonwoo is always grumpy only around him, begins to close the distance. Slowly giving in to Ony's relentless flirting, Yeonwoo finds his heart beginning to pound—the handsome senior might not be so 'Grandpa-like' after all... A sweet campus romance begins between the popular, flirty senior and the gruff, reluctant junior.