  It has been shown that the dispersionless KP hierarchy (or the Benney
hierarchy) is reduced to the chordal L\"owner equation. We show that the radial
L\"owner equation also gives reduction of a dispersionless type integrable
system. The resulting system acquires another degree of freedom and becomes the
dcmKP hierarchy, which is a ``half'' of the dispersionless Toda hierarchy. The
results of this article was announced in nlin.SI/0512008.
