Was your friend female? It looks to me that Jundze might be a feminine form Jundzis, a Latvian surname (whose meaning I don't know). Latvian surnames, like Lithuanian, Polish, etc., have male and female forms. Many Latvian surnames are modified versions of foreign surnames; Russian, Polish, Swedish, German. There are similar German surnames, such as Jundt and Juehne, but there are also Polish surnames beginning with Jundz, some of which might have a Baltic (Lithuanian, Latvian) origin.