Leina writes theme song for Japan-South Korea co-produced film ‘3mm Love’

Singer-songwriter Leina has written the theme song ‘3mm no Koi’ (3mm Love) for the upcoming Japan-South Korea co-produced film ‘3mm Love’. The song features an R&B and jazzy melody, incorporating both Japanese and Korean lyrics to reflect the film’s emotional themes.

The film, scheduled for release on November 6, 2026, is a romantic drama set in Karatsu, Saga Prefecture. It follows the relationship between Tatsuhiko, a high school student, and Yun-seul, an exchange student from Busan, South Korea. The story explores how the two navigate cultural and linguistic differences, symbolized by the ‘3mm’ distance between Karatsu and Busan on a map.

Leina stated that she wrote the song immediately after watching the film to capture the characters' feelings and the film's atmosphere. Specific release details for the single have not yet been announced.