Shouji, a single father, takes his daughter Kana to see a children’s show by the “singing big sis.” However, the show is canceled due to equipment trouble. On the way home, he stops by a diner to cheer Kana up and ends up sharing a table with a suspicious drunk woman. Kana falls in love with the woman and asks her to accompany her home. The woman is the off-duty songstress from the show! Because of her job, she can’t have romantic relationships, and she’s been drinking herself to death because she feels lonely. When she tells him about her situation, the two of them start to become conscious of spending time with the opposite sex for the first time in a long time.
「おうたのお姉さん」の親子ショーを、娘のカナを連れて見に行ったシングルファザーの翔二。しかし機材トラブルでショーは中止に…。その帰り道、カナの機嫌を直すために寄ったファミレスで、酔っぱらった怪しい女性と相席になってしまう。するとカナが女性に懐き、家まで付き添ってもらう事に!?それもそのはず、その女性はオフのおうたのお姉さんだった！仕事柄、恋愛も出来ず、孤独を感じてヤケ酒を飲んでいたというみなみお姉さん。そんな事情を打ち明けると、久々に異性と過ごす時間を２人は意識し始めてしまう。そして、2人の唇は徐々に近づいていき…
