One day I took my son out for a bowl of gyudon, steamed beef over rice, the most popular form of fast food in Japan. The restaurant was crowded, so I added my name to the list, writing “Peter” in the katakana writing system that’s generally used for foreign names and loan words, and sat down to wait. “Everyone else wrote their last name,” my son observed. “Why did you write your first name?” This was an interesting question, and I didn’t have an answer for him right away. Ostensibly, names in Japan are written in family name, given name order, so someone named Taro Yamada in English would be Yamada Taro in Japanese. But by unwritten rule, Westerners always continue to use their name in the same order as they do back home. When I was a teacher, I was universally known as “Peter-sensei” by my students, never “Payne-sensei” as you’d expect. This probably has something to do with the innate “fun” of teachers of English (conversation) , since we’re native English speakers and teach enjoyable lessons and don’t give tests on grammar and vocabulary, unlike teachers of English (the actual academic subject). My students were basically on a first-name basis with “Peter-sensei,” something that would be unthinkable for any of the other Japanese teachers, and this made it easier for me to reach them, I thought.
Foreigners in Japan often end up being called by their given name quite often.