Vibrotactile stimulation to the gluteal or back regions through seats is a promising approach to deliver supplemental information to humans. Designing a method to achieve pleasant vibrotactile stimuli was addressed in this study, as such stimuli tend to result in unpleasant experiences for users. In particular, we investigated the properties of continual vibrotactile stimulation to the gluteal region through experiments and found that decreases in the duration of individual stimuli and vibratory frequency significantly increased the experienced pleasantness, whereas variations in the interval between consecutive stimuli exhibited no effect. Such principles are expected to generally hold in designing vibrotactile signals.