For vicinal surfaces around the (001) surface inclined towards the <111> direction, the influence of roughening transitions on the surface tension and on step droplets is studied numerically. The surface tension is calculated using a restricted solid-on-solid model with a point-contact type step-step attraction (p-RSOS model) on a square lattice. To ensure the reliability of the calculations, the density matrix renormalization group method is used. The growth rate of the vicinal surface near equilibrium is also calculated by the Monte Carlo method. It is found that the roughening transition changes the morphology around the (001) surface, and the roughening transition affects the size of locally merged steps (step droplets).