Miu works in R& D of an underwear company; D department is an underwear investigator. Miu (Deng Lixin) is diligent and studious, but he loves fantasy but never has the taste of dating. However, after moving into my aunt's former residence (Michelle Lo), Miu realized something. It turned out that although my aunt had a successful career, it was a pity that Yunying was unmarried and died a virgin. There is a room full of beautiful underwear of different styles, but there is nothing to show. Miu, who doesn't want to be an old aunt, is determined to find a man to taste the first love. Word spread like wildfire, and a large number of suitors emerged around Miu, including Prince Antonio (Huang Zulin), Xinrui (farmer, Wing-kuen Luk) and bank manager (C Jun). Miu has been confused, when a "love expert" Lucas (Zheng Zhongji) appears and takes a fancy to her. Fortunately, several good sisters, Donuts (played by Janice Man), Celine (played by Yi Tang) and CC (played by Jia Xiaochen), helped her, from which she was inspired by underwear and love relationship, which gave Miu a new understanding of love and men.

My cousin Donut, who lives with Miu, is a shop assistant in underwear store. She was only interested in mature men and mistakenly developed a triangular relationship with the son of a mature boyfriend. A frequent visitor to the donut underwear store is a dusty woman, who is very good at treating male guests, but will never have real feelings with male guests. It happened that the appearance of pure Eugene (Andy On) made Xixi fall in love. Celine, the neighbor of Miu and Donuts, is a stewardess. Marrying a rich man is her unshakable ideal, but the appearance of a poor boy (Xu Tianyou) takes good care of her and develops a "fooling around" love.

Miu's innocence in love moved Lucas, who decided to become her love consultant and chose a man for Miu, himself. Donuts don't want the last two, and her breakup was made into a movie and became a popular online short film. Poor CC woke up and was taken away by innocent Eugene, including her heart still in love. In the end, Celine's dream of marrying into a rich family remains unchanged, but she is willing to wait for the day when this poor boy has a successful career. Everything gives Miu a new understanding of love and men.