just had a proper listen to that cover version ; in the German version the singer is around the same age as the Japanese boy (in her teenage years) who is in Germany as his parents have migrated there – she notices him wandering the streets alone (there were a fair few Japanese who moved to small coastal areas of Germany to work on marine stuff) and makes the first move as he has apparently forgotten the route back home.
The lyrics (which would have had to be appropriate for a 14 year old to sing on daytime TV) imply that would thus get to meet his family and it turns into a long term relationship (arranged marriages were still common even in Europe!) so that bit might not have been such a culture shock for him…
