We report the direct imaging detection of a low-mass companion to a young , moderately active star V450 And , that was previously identified with the radial velocity method . The companion was found in high-contrast images obtained with the Subaru Telescope equipped with the HiCIAO camera and AO188 adaptive optics system . From the public ELODIE and SOPHIE archives we extracted available high-resolution spectra and radial velocity ( RV ) measurements , along with RVs from the Lick planet search program . We combined our multi-epoch astrometry with these archival , partially unpublished RVs , and found that the companion is a low-mass star , not a brown dwarf , as previously suggested . We found the best-fitting dynamical masses to be m _ { 1 } = 1.141 _ { -0.091 } ^ { +0.037 } and m _ { 2 } = 0.279 ^ { +0.023 } _ { -0.020 } M _ { \odot } . We also performed spectral analysis of the SOPHIE spectra with the iSpec code . The Hipparcos time-series photometry shows a periodicity of P = 5.743 d , which is also seen in SOPHIE spectra as an RV modulation of the star A . We interpret it as being caused by spots on the stellar surface , and the star to be rotating with the given period . From the rotation and level of activity , we found that the system is 380 ^ { +220 } _ { -100 } Myr old , consistent with an isochrone analysis ( 220 ^ { +2120 } _ { -90 } Myr ) . This work may serve as a test case for future studies of low-mass stars , brown dwarfs and exoplanets by combination of RV and direct imaging data .