This is a hot spring episode that knows exactly what it is: three magical girls doing nothing in particular, and somehow that's enough. The OVA doesn't pretend to matter. It just wants you to sit with these characters in warm water while the world stays quiet, no stakes, no saves needed. For 1986, that's restraint. For a mahou shoujo special, that's almost radical.
Mami, Persia and Emi, three magical girls, head off to a hot spring together in this one-episode OVA from 1986. The special is a crossover that brings the three heroines into the same story, and much of its running time is given over to recap material. Its genres are comedy and magical girl, so expect a light outing built around the shared trip.