In Japan (nowadays, anyway), foreign movies are usually simultaneously screened in dubbed editions 'for kids', and subbed editions 'for adults'. There are a lot of practical issues associated with subbing titles directed at kids (varying levels of reading ability among the target audience, having to clutter up the subs with tons of furigana, etc.), issues which go beyond 'kids are lazy and don't want to read', lol. Nowadays, films generally get simultaneous international releases due to American studios having deals with international studios, better translation pipelines, etc. but I'm not sure what the pipeline would have looked like in the 80's.

(Where in Japan are you going? I lived in Hatogaya-shi/Kawaguchi-shi, Saitama-ken for a year when I was attending Jouchi.)