Trick.. Yukie nakama poor magician and Abe Hiroshi a rich professor..
There is another one that name I've forgotten, where the main guy was a rich professor and a poor student helps him solve cases. He gets more famous and she gets money to pay bills and rents.
Another is after dinner mystery..
Kitagawa keiko pretends to be a poor woman and helps a silly detective who is rich to solve cases.
But Kitagawa keiko is actually very rich and it's her butler who actually solves the cases..