They have notoriously bad breath and bad teeth. Travel guides for Japanese tourists even suggest they brush their teeth regularly and use mouthwash in America so as not to offend people.
Is this a joke? Japanese brush at least three times a day. Probably more than in most western countries. And they have tons of breath fresheners in convenience stores. You would not have such products if no-one was buying them.
This being said, I can certainly relate to the cigarette smell, but that's not only a breath issue, that kind of smell sticks to everything, from clothes to interiors.
Have you ever been to Japan? In my travels there I have not noticed any unusual halitosis, and I've spent plenty of time packed into the metro at rush hour.
