Gu Xiaojiao (Tong Liya), a broke thirty-something luxury sales assistant, wakes up one morning next to a complete stranger, Lu Ming (Lei Jiayin), an equally broke real estate salesman. The thing is, they’ve both been living in the same flat, but she occupies it in 2018, and he occupied it in 1999. And through a freak space-time disruption, the flat has become a crossroads between both years: the entrance door now has a handle on the left and a handle on the right: if they open one they’re in 1999, and if they open the other they’re in 2018. After some initial hostility and adjustments, Xiaojiao and Ming decide to use this anomaly to their advantage.

Yet another time-traveling comedy from China, Su Lun’s How Long Will I Love U milks the concept, much like Han Han’s Duckweed or Yan Fei and Peng Damo’s Goodbye Mr Loser, both for soft nostalgia for an apparently simpler – albeit not far removed – time, and for (very) mild social commentary on the exponential rise of materialism in China. And like Zhang Mo’s Suddenly Seventeen or Leste Chen’s Miss Granny, it has its protagonists accept the mind-blowing space-time anomaly very quickly, for the sake of brevity and lightness of tone. There’s some interesting visual flourishes, such as when both Xiaojiao and Ming go to work in their respective timelines, with a split screen showing them walking the same streets, with subtle and less subtle changes in evidence.

Rather than let her concept fly, Su Lun (who wrote the screenplay based on an idea by Xu Zheng, who also produces and has a funny cameo) unfortunately has a mad scientist character on call to half-assedly explain it, and there’s a dash of danger near the end of the film that’s too contrived (especially in the way it wants to link Ming’s past to Xiaojiao’s) and threatens to stop the film dead in its tracks. Luckily, Tong Liya is an immensely attractive lead who powers every scene with deft shifts in mood, while never becoming annoying in the process. Her chemistry is fine with a solidly likable Lei Jiayin, but the latter is too often overshadowed by his co-stars full-on charm offensive and impeccable comedic timing, though he does shine when the story calls on him to play two wildly different versions of his character. The film also benefits from an ending that is not the usual neat, happy narrative bow, but has a bittersweet ambiguity to it.

Long Story Short: Powered by Tong Liya’s considerable talent and charm, Su Lun’s How Long Will I Love U is a solid but often contrived time-traveling romantic comedy. **1/2