Double Section

Nakai, an auditor from an insurance company is already used to being glared at by the people from his line of work, so when his neighbor happily smiled at him, he's surprised and glad. But that did not stay for too long when it turned out, his neighbor Takahashi is the assigned salesperson he need to deal with because there's a problem regarding to the client and moreover Takahashi hates auditors like Nakai. What will happen to this neighbors whose jobs are like water and oil?