Due to the increasing density of rail networks, the time for the G402 high-speed train to stop at Xinxiang East station was cut from six minutes in 2016 to two in 2019.

Each one of the couple has responsibilities of his or her own in this two minutes. Zou is required to station at the door while Li has to serve the passengers. No contact is made other than picking up the bag through the door.

Sometimes the two get so busy that they even don't have time to meet. In such cases, Li leaves the bag by the door, while his wife pulls down the window shade to the upper third -- it is their "missing-you" code.