A Fast spin echo (FSE) pulse sequence has been a main workhorse for clinical imaging due to its flexible contrast. Simultaneous multi-slice (SMS) FSE in  was shown to be efficient for slice acceleration without much loss of signals. Nevertheless, the previous SMS FSE methods, which employ high-flip-angle, spatially-selective multi-band RF pulses for both excitation and refocusing, still remain sub-optimal due to either high energy deposition or elongated echo spacing (ESP) and thereby limited echo train length (ETL). The purpose of this work is to develop a novel, slice-accelerated single-shot variable-flip-angle (VFA) FSE with very long echo trains, in which multi-band RF pulses are used only for excitation while short hard pulses with VFA are utilized along the refocusing pulse train, enabling very short ESP and very long ETL and thus enhancing imaging efficiency. It is shown that the proposed method makes it possible to complete whole brain imaging within 30 sec without apparent artifacts and noise.