Shingo Aino used to work as an associate professor of ethology. He now works as the director of a matchmaking agency. His assistant is Sister Elizabeth. The high entrance fee at the matchmaking agency is two million yen, but the matchmaking agency has a 100% success rating for their clients getting married. They match customers based on the client's conditions. The secret behind their 100% marriage rate is Shingo Aino's counseling, relying on his knowledge in ethology.