Childhood promises are often taken light-heartedly, but what happens if an innocent little girl mistakes a dismissive comment from her tender years as a commitment tor marriage? That's exactly what happens when Yuka asks Ryo to keep his promise to marry her -- even though it was 10 years ago! But the kind-hearted Ryo just can't find it in him to give it to her straight, and so ensues a wacky comedy of silly cover-ups and failed attempts to set the record straight!