I've lived in the same small-sized city (about 43,000 people) in Japan for the past two years now. Since I teach at four junior high schools and seven elementary schools, many, and I mean many, students know who I am. As of now, most students currently in their first or second year in high school, know of me because I taught them.
You know what this means, right? I can't go anywhere in this town without a student seeing me and sometimes with a very surprised look on their face saying out loud, "Oh! It's Ms. Diana!!" in Japanese. That's from the more outgoing kids. The quieter ones would just nod their head (nodding one's head is a simple sign of saying "hello" in Japan.)
I'm used to seeing my kids from JHS and ES and I can usually tell that they are my student because of their school uniform. However, with my former students that are in various high schools (with different uniforms mind you), it's difficult to tell if I was the one that taught them as a JHS student. So, it really makes me happy when former students say hello to me. There are quite a bunch of whom I miss a lot.