I don't think these figures include the extramarital activity. But I've read the infidelity rate doesn't vary all that much (roughly 30% of men, 20% of women) between the two countries . . . despite all the hype, movies and publicity.
FWIW, I was a salaryman for 14 years and worked roughly the same hours as my Japanese counterparts (Japanese companies). The longer working hours are mitigated somewhat by the greater number of public holidays and greater ease of taking time off for family matters, at least in the larger companies. My last company allowed 22 such days in a year.
Less than Americans huh? Glad I’m here.