Inemuri translates roughly to “snooze” or “doze”. There is no dirrect translation, however “sleeping while being present” or having some awareness about you while you sleep is potentially more accurate.
It very common, in fact, an every day experience, to see Japanese people sleeping in public places. Most regularly, on trains. It is quite alarming at first. It is almost as if a wave of collective narcolepsy has overtaken the train carriage. However, you soon become accustomed to seeing people sleeping all over the place. I have seen people on crowded carriages leaning up against each other, back to back. Sleeping. While standing. It is quite extraordinary.
In general, the sleeping people do seem to maintain the customary personal space and manners you would expect in Japan. There is no falling sideways into other commuters or encumbering another passenger with baggage.So, I guess there must be some semblance of “being present”. I have seen someone who was enjoying inemuri in the middle of a busy footpath who was totally oblivious. It was a Friday evening in Shinjuku in Tokyo. He was a salary man, and he was very drunk. Interestingly, everyone very politely stepped over him. No-one made disparaging or derogatory comments. There is no shame in sleeping in public, or in getting completely legless, for that matter.
The photo I have added shows my eldest, aclimitising themself very quickly to join the snoozing locals…..