carol (5th grade elementary school) likes kotarou (25), the guy who live in her house, but she is aware of herself who has limitations, she realized that she, who was still a child, would not be able to win kotarou's heart, things got worse, when she found out that kotarou was dating her friend's sister, chizuru, she cried, knowing that she was not commensurate with her friend's sister, who was tall, had plump breasts, and was an adult, that night, she wrote in her diary “i want to be an adult” in lines, until what she wants is carried away in her dream, when she's awake, there is a strange woman in front of her, she claimed that she was named ai who was also the daughter of carol and kotarou who had come from the future, this is a story, where ai will help carol (mama) to unite with kotarou (father). indonesian: :spoiler carol (kelas 5 sd) menyukai kotarou (25), orang yang menumpang tinggal di rumahnya, namun dia sadar akan dirinya yang mempunyai keterbatasan, dia sadar dirinya yang masih anak-anak tidak akan bisa memikat hati kotarou, hal itu semakin bertambah buruk, ketika dia tahu bahwa kotarou jadian dengan kakak temannya, chizuru, dia menangis, tahu bahwa dia tidak sepadan dengan kakak temannya, yang tinggi, berpayudara montok, dan sudah dewasa, malam itu juga, dia menulis di buku hariannya “aku ingin menjadi dewasa” berbaris-baris, hingga apa yang diinginkannya tersebut terbawa mimpi, begitu terbangun, ada wanita asing di depannya, dia mengaku bahwa dia bernama ai yang juga anak carol dan kotarou yang datang dari masa depan, ini adalah cerita, dimana ai akan membantu carol (mama) untuk bersatu dengan kotarou (ayah).