Responses

it's not useless to cite them, because all surveys have different contexts. mine was admittedly mis-cited, because it actually refers to how many japanese men WOULD cheat on their partner if they were absolutely sure the partner wouldn't find out. the number is extremely high. your survey is about how many japanese men HAVE cheated on their partner. and that is a high number, as well; that's one in five men.
meaning: 1 in 5 men cheat on their partners and more than 6 in 10 men would cheat on their partner if their ideal conditions were met. conclusion: 2/3 of japanese men are trash.
according to surveys, 64% of japanese men cheat when in a relationship. so this problem is more than common in japan, unfortunately.