  We have studied the Gamow-Teller (GT) transitions from $N=Z+2$ neighbors to
$N=Z=$ odd nuclei in $p$-shell region by using isospin-projected and
$\beta\gamma$-constraint antisymmetrized molecular dynamics combined with
generator coordinate method. The calculated GT transition strengths from $0^+1$
states to $1^+0$ states such as ${}^{6} \textrm{He}(0_1^+1)\rightarrow{}^{6}
\textrm{Li}(1_1^+0)$, ${}^{10} \textrm{Be}(0_1^+1)\rightarrow{}^{10}
\textrm{B}(1_1^+0)$, and ${}^{14} \textrm{C}(0_1^+1)\rightarrow{}^{14}
\textrm{N}(1_2^+0)$ exhaust more than 50\% of the sum rule. These $N=Z+2$
initial states and $N=Z=$ odd final states are found to dominantly have
$S=0,T=1$ $nn$ pairs and $S=1,T=0$ $pn$ pairs, respectively. Based on
two-nucleon ($NN$) pair picture, we can understand the concentration of the GT
strengths as the spin-isospin-flip transition $nn(S=0,T=1)\rightarrow
pn(S=1,T=0)$ in $LS$-coupling scheme. The GT transition can be a good probe to
identify the spin-isospin partner states with $nn$ pairs and $pn$ pairs of
$N=Z+2$ and $N=Z=$ odd nuclei, respectively.
