Hakucho observations have revealed that the soft transients, 2S1608‐522, 2S1715‐321, CenX‐4 and Aq1X‐1, all generate X‐ray burst. This result makes it convincing that these sources involve neutron stars. Furthermore, the optical counterpart of Aq1X‐1, when X‐ray quiescent, is identified to be a ∼KO dwarf, thus providing evidence that Aq1X‐1 is a binary of a late dwarf and a neutron star.Soft transients in the flare state are similar in X‐ray and optical properties to so‐called bulge sources. This and the observed high association of soft transients and bulge sources with bursters seem to indicate similarities of both to Aq1X‐1. Flare‐up of the soft transients is considered to be caused by episodic mass accretion.