A suite of 24 pieces composed between 2000 and 2009. Each piece is about two minutes long. In 2009, the complete version was premiered by Kazue Nakamura at Monnaka Tenjo Hall. Yori-Aki Matsudaira used pitch interval technique in this work. In the odd-numbered pieces, fundamentals are the first note, the second note, etc. of the tone row of the first piece. In the even-numbered pieces, the fundamentals are the first note, the second note, etc. of the tone row of the second piece. Besides, the interval between the first note and the second note of the tone row is minor second, major second, etc. in the odd-numbered pieces, while that is major seventh, minor seventh in the even-numbered pieces (from the 11th to the 14th piece, however, the interval between the sixth and the seventh tone is always augmented fourth). The titles of the odd-numbered pieces begin with A, B, C, etc. and those of even-numbered pieces X, Y, Z, etc. It should also be noted that atonal chords are used in the odd-numbered pieces, and modal chords in the even-numbered pieces. Though the tempo is approximately at 60 per quarter note, meter and texture freely change in a piece. While repetitive notes often appear as in Allotropy, the 14th piece ‘Transition’ in which tempo becomes twice slower repetitively or the 23rd piece ‘Legend’ including the citations from Stockhausen’s Klavierstück I-XVII, shows that Matsudaira’s creativity does not decline at all. The score was published by Sonic Arts.