Shirota (Shota Matsuda) has just started his dream job as a child welfare caseworker. Filled with a sense of responsibility, he has been working hard every day, but since he is meek and tends to adhere to instruction manuals, he is considered a burden by his colleagues.
In contrast, Sabashima (Katsumi Takahashi), leader of local mafia group Sabashima-Gumi, has his sights set on becoming the next boss of this mafia organization.
One day, Shirota heads out to follow up on a report of child abuse while, at the same time, Sabashima goes to collect loans. They both enter the same apartment building when a ray of light covers this building, resulting in a quirky body switch!
Not knowing how to regain their original appearances, they decide to pretend to be the other man for a while. Shirota tries to behave like Sabashima to make sure Sabashima's wife Ayumi (Yuki Uchida) and the members of Sabashima-Gumi don't find out the truth, whereas Sabashima also tries to behave like Shirota to make sure his colleagues at the child consultation center don't realize that something is amiss.
Therefore, Sabashima (whose appearance is Shirota, the caseworker) had no choice but to continue child welfare work by checking on children who refuse to go to school or who may have been abused by adults. Not at all a natural with young ones, Sabashima tries to deal with these troubled children in his own way, which is nothing like what the instruction manuals dictate.
Can all these troubled children be saved?!