“But… we’re like siblings.” Cha Seung-jo, a football player every Korean knows, and Lee Seo-hee, who grew up in the same household as him, share a bond like brother and sister. At 18, Seung-jo confessed his feelings to Seo-hee— but after that, he never once returned to Haeyoung, where she lived. Six full years passed. “I endured it all until I succeeded, until I became a real adult.” “Six years is enough. Don’t tell me to wait any longer, Seo-hee.” Now, Seung-jo returns as a grown man— no longer the 18-year-old boy he once was. Maybe that’s why… Seo-hee feels her heart race differently than it did six years ago. “Just for ten days… let’s date.” Seo-hee must now make her choice: continue living like siblings, pretend not to know, or finally… become lovers.