“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.