Gamow-Teller (GT) transitions are mediated by the sigma tau operator. Owing to its simplicity and also its spin-isospin nature, GT transitions play key roles in the studies of nuclear structure as well as astro-nuclear processes. In violent neutrino-induced reactions at the core-collapse stage of type II supernovae, Gamow-Teller (GT) transitions starting from stable as well as unstable pf - shell nuclei play important roles. We study GT transitions starting from Ti-47 in a high-resolution (He-3, t) charge-exchange reactions at 0 degrees. and at an intermediate incident energy of 140 MeV/nucleon at Research Center for Nuclear Physics (RCNP), Osaka. Individual GT transitions up to high excitations were observed. Assuming the isospin symmetry for the strengths of T-z = +/- 3/2 -> +/- 1/2 analogous GT transitions, we can deduce the detailed strength distribution starting from mirror unstable nucleus Mn-47.