You can shift air conditioning, to a degree. You could cool down the house, maybe even one or two degrees under your usual temperature. Your house now acts as a thermal battery and you can leave the AC off for some time. How long will that work? With the general atrocious insulation in Japan and the very humid/hot summers, probably not super long.

Of course not super on topic but the insulation in central Japan seems to be a big problem to me. Walls are thin and often made out of wood. There are ventilaton holes, often closeable, but with the thinnest plastic cover. Windows are single pane, and the window frames and doors are often of such shoddy construction, you can see the outside through some cracks. If there was a shift in construction quality, I'm sure the electricity use in summer and winter would drop, but I don't expect that to happen soon. Insulation and construction quality is expensive, so this isn't done in construction of rental apartments.