In this letter, we propose to reduce the detection complexity of soft-decision aided Space-Time Shift Keying (STSK). More explicitly, we propose a vector-by-vector based STSK detector, which exhibits a lower complexity compared to the classic block-by-block based Space-Time Modulation (STM) detector. We further operate the STSK detector on a symbol-by-symbol basis, so that a near-capacity performance may be achieved with the aid of channel coding at a reduced complexity.