  We study transport through a triangle triple quantum dot connected to two
noninteracting leads using the numerical renormalization group (NRG). The
triangle has a high-spin ground state of S=1 caused by a Nagaoka
ferromagnetism, when it is isolated and has one extra electron introduced into
a half-filling. The results show that the conduction electrons screen the local
moment via two separate stages with different energy scales. The half of the
S=1 is screened first by one of the channel degrees, and then at very low
temperature the remaining half is fully screened to form a Kondo singlet. The
transport is determined by two phase shifts for quasi-particles with even and
odd parities, and then a two-terminal conductance in the series configuration
is suppressed $g_{\rm series} \simeq 0$, while plateau of a four-terminal
parallel conductance reaches a Unitary limit value $g_{\rm parallel} \simeq
4e^2/h$ of two conducting modes.
