In the "ah, so this is culture" file, i am pleased to report overwhelming evidence indicates touching people is ever-so-common all-the-time here (between people for whom sexual rapport is thought to be impossible). that is, people will crowd you on the trains, sit basically on your lap at the public benches, ram against you in line, elbow you getting on a bus, tug your arms, put their babies against your bosom, hold your hand, touch your head, stroke your beard, grasp your side, etc.
but! if anybody accidently steps on you or brushes you with their Feet, there is an immediately apology in the form of touching your feet with their hand and then touching that hand to their heart or head. as in, touching you with their feet (as opposed to babies or elbows) is denigrating and disrespectful and begs for immediate atonement.
so that's cool. or, at least, what it is.