My 3-year-old daughter is in a public state of high excitement. She jumps up and down emitting toddler squeals of joy before darting away from me, past staring crowds, in the hope that I will chase her. Oh, and she's completely naked.

Fortunately, we are in one of the few places in Tokyo where not wearing any clothes is perfectly acceptable (and where thankfully, people also seem to turn a blind eye to exuberant toddlers) — namely, an onsen (spa).

The Japanese pastime of hot spring bathing may evoke images of serene soaking in muscle-melting waters, while appreciating the passing of seasons and meditating on the fleeting nature of life.