Tsubaki feels responsible for the scar he left on Yuu's face years ago, when the two were close friends. Determined to make up for it, he wants to grow up big and strong so he can protect his oldest friend. The problem is simple: Yuu is already a high schooler while Tsubaki is still in elementary school. What drives Tsubaki isn't only responsibility, though. He is completely smitten with the gentle, easygoing Yuu, who always treats him kindly but can't see him as anything other than a child. Tsubaki is sure his feelings will reach Yuu someday, and that Yuu will come to lean on him. The result is a quiet romance about innocence, admiration and growing up.