To accomplish a superior characteristic for absorbing and damping torsional vibrations in a damper disk assembly and a flywheel assembly. A damper disk assembly includes a pair of plates 11 and 12, a flange 20, coil springs 16 and 17, and friction plates 58 and 59. The pair of plates 11 and 12 is fixed to each other. The flange 20 is disposed between the pair of plates 11 and 12 in the axial direction. The coil springs 16 and 17 elastically couple the pair of plates 11, 12 and flange 20 in the rotational direction. The friction plates 58 and 59 are disposed to operate in parallel with the coil springs 16 and 17 between the pair of plates 11, 12 and the flange 20 in the rotational direction, frictionally engage with the pair of plates 11 and 12, and engage with the flange 20 to be relatively rotatable in only range of the small torsional angle.