I made a wish on my birthday and I became a child?!

On her birthday, she made a wish to become a baby, and when she woke up, she had become a real child. She also occasionally mysteriously returns to her original age of 19. She calls her older brother to tell him her situation, and Seungmin tells her not to act like a fool, revealing that he is Wanna One's manager and suggesting they live together. Yeo-ju accepts the offer, and the romantic comedy about Yeo-ju and Wanna One, who have become children, living together and nurturing Si-rang's buddin