"During our preparations before filming, we refined the theme of hometown, based on Gulangyu," Liu says.

"We found that two major groups living on the island, the local people and those who migrated there, both had affection for the place. It's literally the hometown for local people, and a second hometown for the migrants."

Then they combined this theme with young people's struggles in big cities, an important topic of the times, and created the story. "In this way, besides showing the city, we also show the reality that many young people face when making choices about where to settle down: to struggle in big cities or go back to hometowns," she says.

The production is also part of the team's effort to seek out common emotions, she adds.