The album was inspired by Pupul's Hong Kong-born Chinese mother, Yu Wei Wun,[1] who died in a car accident in 2008.

[2][3] Pupul took a trip to Hong Kong in 2018, and per a statement, "On the first day I arrived in the city I visited the street where she was born and wrote her a letter.

[2][3] With the announcement came the lead single, "Completely Half", and a music video shot in Hong Kong by director Bieke Depoorter.

[14] Loud and Quiet's Joe Goggins called Letter to Yu "an endearingly intimate album that captures the thrill of Zeebroek's immersion in his ancestry.

"[1] The Arts Desk's Joe Muggs called the album "quite a magical record that honestly doesn't need all that much explanation to enjoy hugely.

"[16] Pitchfork's Eric Torres wrote that "Pupul imbues his songs with personality and soul, unearthing complicated truths about his relationship to his heritage while finding welcome release on the dancefloor.