Nibbler

The woman in the Kyoto Tower branch of Starbucks eats a muffin the size of her head with a knife and fork, slicing off pea-sized crumbs once every few minutes, and munching them very slowly and deliberately.

The woman standing next to me on the train to Ikebukuro spends the entire 40 minute journey playing with a virtual dog on her phone, feeding it virtual snacks and making it fetch virtual sticks. Every few minutes she mops her sweat-soaked brow with a small towel she keeps draped around her neck.