Commissioned and premiered by Mitsuko Kado at Casals Hall in March 1997.

One day, reflecting on the close resemblance between the Japanese words 'tsuiraku' (fall/crash) and 'daraku' (degeneration/decadence), I conceived a series of compositions for a fictional dance titled 'Tsuiraku Buto' (Falling Dance / Decadent Dance). For each piece, I decided to use a Japanese translation of a Western musical form as its title. Other works in this series include 'Tsuiraku Buto Koshinkyoku' (Falling Dance March) and 'Tsuiraku Buto Kikyokukyoku' (Falling Dance Capriccio).

Why this particular work became a 'Tonsokyoku' (Fugue) (though I recall it was intended for keyboard instruments), and how I composed it (I must have been somewhat conscious of 'Fuga')... these details escape me entirely, as it was 13 years ago.

This piece marks my first piano solo composition. While it is common for music students to compose at least one piano solo piece during their studies, this work was composed two years after the completion of my academic life.