JoJo's Bizarre Adventure - Kakyoin is very helpful

For anyone who doesn't understand how Japanese work, Kakyoin literally spell every fucking words out in case Jotaro can't read them, even his name.

Additional information:
Stardust Crusader was published in Shonen Jump which is for young boys and furigana is used to help them who still have problem reading kanji.

They probably just being true to the source.