When I first arrived in Japan when I studied abroad there in Fukuoka, I was trying to ride the subway/train system for the first time to get to school. Unfortunately I got off the subway one stop past where I was supposed to go.
The problem being, my card that paid for my transportation, given to me by my host family, only paid from the stop where our home was in the country, to the stop to where my school was in the city.
I went over to the police officer once I figured out where I was, and asked him if I could get on the subway to go back one stop as I missed the stop accidentally since I couldn't read the signs yet at that point. He was actually very short and abrupt and called another officer over, who in broken English told me I couldn't get back on the subway even if I paid. Needless to say, I was only there one day before and I was very very scared. First time abroad and I was already in trouble (seemingly) with the authorities.
The only thing that saved me was that my host sister (may she rest in piece), had made me a notecard the previous day that basically said something to the effect of "My name is _____, I'm not from here, I have no idea what I'm doing or where I'm going. If you find me, please point me in the direction to either go to school or home" with the following addresses listed.
The police offers had a very hearty laugh at my expense and let me get on the subway train. If it wasn't for that card, I don't know if I could have figured out where to go up above as it was my first day in the city on my own, and I was only showed one way to get to the school on the previous day with my host mother's help.
Other than that though, my stay there for those months was more than pleasant. Other than that one time of being scared, almost everyone was MORE than helpful to me. People would want to talk to me in English on the train just to test out their skills, and when I was lost once, a lady who worked in one of the downtown malls walked me all the way down 4 stories, across the street, and to the store I was trying to get to. Amazing.
The only other time I was treated not with open arms was when I went to get my haircut. Over there they think having REALLY short hair on the sides is hystaricle apparently, and I was always on the raw end of many jokes while the lady cut it.