¡°I think they¡¯re having an affair,¡± murmurs my companion, the ever-observant Megumi. She nods at a middle-aged couple sitting next to us on the ¡°Romance Car,¡± the limited express train that links Tokyo and the hot-spring resort of Hakone, Kanagawa Prefecture.

¡°How can you tell?¡± I ask.

¡°They¡¯re too flirtatious. At their age, married couples don¡¯t have that much fun.¡±