Friend of mine worked in Japan for a while & said scenes like this were not uncommon - he crashed out drunk on the metro a couple of times after heavy nights out & woke up surrounded by early morning commuters who were thankfully too polite to even acknowledge his stinking presence.
The last train to my apartment, Shinjuku to Kichijoji, was so busy on a Friday and Saturday night that I could pass out and be held upright by the crush of people, with the majority getting off at my stop and waking me up in the process.
To be honest, the guy on the tube. We have all had a bad morning/night like that.