Served as an undercover for several years, Leung Siu Tong or Laughing (Michael Tse) escaped from all calamity. Two years ago, he underwent special training, pretending to be mute and sneaked into an armed robbery gang as a spy. He successfully solved the criminal case and later became an instructor for special training in undercover work. Unfortunately he was unable to adapt to the stress in the discipline, so he applied to be an undercover once again. His supervisor Chief Inspector Jodie Chow Mong Ching (Fala Chen), looking exactly like his deceased girlfriend, was the person he communicates with during his undercover work. A female inspector and an undercover, falls into a black-white romance, and eventually became a pair that is in love, but cannot love…

The Special Mission Task Team is not considered as important as it might sound. It is positioned in the lowest section of the Metropolitan Police Department and headed by Ukyo Sugishita. Together with his partner, played by Terawaki Yasufumi, this team is Japan’s version of The Odd Couple, solving clueless cases in original and outrageous ways.

Maysarin is a famous socialite who's engaged to Sarut, but he left her on the day of the wedding. Kadethaen is a 30 year-old real estate businessman who's waiting for Pinmanee, his bride at the reception of a luxury hotel, but he saw her escape the wedding with another man. Kade walked out to a party at the beach, where he met May, who was still in her wedding dress drinking alone. They started drinking together and people thought they were a couple, so they went along with it and he jokingly proposed to her. Afterwards, they went back to the hotel and spent the night together.

In the morning, May regretted what happened and wants to forget about Kade, but he's not going to give up on her.

Kang Jae is a wealthy businessman and gangster and Mi Joo is a plastic surgeon. These two meet after Mi Joo mistakes Kang Jae as being her sleazy brother-in-law. Kang Jae just happens to be the boyfriend of Mi Joo's pregnant neighbour, Yoo Jin. Sae Yeon meets Mi Joo and falls in love with her feisty attitude. Kang Jae works for the father of Sae Yeon who is a gangster. Mi Joo and Kang Jae fall in love.

Blessed with good looks, Takano Kyohei, a college student, is always suffering from the unreasonable behaviour of customers who want him and the sexual harassment of his store manager. Because of his hot temper, he loses his head on this occasion and is fired from his part-time job. Then one day, the glamorous owner, Ms Nakahara proposes, "I'll give you free board-and-lodging if you can turn my niece, Sunako, into a lady!" Kyohei and Toyama Yukinojo, Oda Takenaga and Morii Ranmaru, the other guys living together in the same boarding house, are enthusiastic, but the person who appears before the four of them is a spooky girl whose hair covers her face and who loves horror and vampires. And so, their tumultuous communal life begins.

Adapted from the manga "The Wallflower" (ヤマトナデシコ七変化) by Hayakawa Tomoko (はやかわともこ).