Face it, you need to get out of Tokyo during the dog days of summer, when it gets like a fetid sauna.
Yeah, you can while away a few hours at an outdoor beer garden and dull the pain, but basically you know you have to escape.
The well-known retreats of Nikko, Hakone, Kamakura, Karuizawa and Izu have their allures, but are often overrun, overrated and already in the "been there done that" heap.