Isabell Rohde's job is to take care of and play with Yoyo. [Photos Provided by Chongqing Holiday Cultural and Tourism Exchange Center]

In China, the demand for au pairs has started to grow in recent years as some affluent and ambitious Chinese parents want their children to get a hands-on feel when learning a foreign tongue.

In 2014, a Chinese movie, When a Peking Family Meets Au Pair, drew public attention to this concept.

Based on the experiences of a Chinese host family, the movie is about how a traditional Chinese family gets along with a Colombian au pair called Natalie.

Yoyo's father Pu Yongjian, an economics professor at Chongqing University, learnt about the au pair program this year through an English teacher whose friend is running an au pair agency in Chongqing.

"My son likes English very much, so I want to have an English-speaking au pair to help him practice the language at home," says Pu.

But at first, the agency told him it might take a while to find an au pair who wants to come to Chongqing, a lesser-known Chinese city in the underdeveloped western region.

Typically, foreign au pairs want to live in Beijing and Shanghai.

"Bai Mei (the Chinese name Pu gave to Rohde, which means white plum blossom) is an exception," says Pu.

"She wanted to go to the 'backward' part of China."

My academic and professional background also attracted the German student who plans to pursue an economics degree in college when she returns home, the professor says.

Explaining how au pairs and families are matched, Ma Senhu, the general manager of the Chongqing Holiday Cultural and Tourism Exchange Center, which helped Pu find the German au pair, says: "Our clientele comprises well-educated professionals with international exposure, such as professors, lawyers and entrepreneurs."