This OST from Monstar by Kim Bum Soo and Lena Park is in C, Eb and G.
These are the “cheat” chords I played…
Intro: C2 - Am7 - Dm7 - G11
Part 1a: C2 - F/A
Part 1b: G - C2 - G/B
Part 1c: Am7 - Am7/G - F2 - C/E
Part 1d: Dm7 - G11 - Bb11
Part 2a: [...]
