FamousPrincess Mononoke1997 · Joe Hisaishi
Bars 1–2 of the song's introduction; bars 3–4 repeat the shape a whole step lower (B♭ C E♭ F)
Four notes, C, D, F and G, packed close together over C with no third, so the chord is neither major nor minor. It opens the introduction of the Princess Mononoke theme song, which is in C minor, and then moves down a whole step to the same shape on B♭. Rearranged as D–G–C–F it becomes a stack of fourths, which gives the intro its hollow, ancient sound.
Also called Mononoke sus, Csus4(9)
Not yet confirmed by a second source.
Sources: TakKa, 【コード分析】「もののけ姫」の前奏のコードは四度堆積和音？ (Takka note blog, 2021-04-17) · U-FRET chord chart: もののけ姫 / 米良美一 · Hooktheory TheoryTab: Mononoke Hime