We study vacua, walls and three-pronged junctions of mass-deformed nonlinear sigma models on $SO(2N)/U(N)$ and $Sp(N)/U(N)$ for generic $N$. We review and discuss the on-shell component Lagrangians of the ${mathcal{N}}=2$ nonlinear sigma model on the Grassmann manifold, which are obtained in the ${mathcal{N}}=1$ superspace formalism and in the harmonic superspace formalism. We also show that the K{a}hler potential of the ${mathcal{N}}=2$ nonlinear sigma model on the complex projective space, which is obtained in the projective superspace formalism, is equivalent to the K{a}hler potential of the ${mathcal{N}}=2$ nonlinear sigma model with the Fayet-Iliopoulos parameters $c^a=(0,0,c=1)$ on the complex projective space, which is obtained in the ${mathcal{N}}=1$ superspace formalism.