Board Thread:Manga Discussion/@comment-28656082-20160605033723

I realized that because Kira's mother is Holly Joestar and Josefumi's Father is the alternate Sadao Kujo, Gappy being a fusion of Kira and Josefumi he is technically the son of Sadao and Holly. So it seems that it would make more sense for Gappy to be the alternate world version of Jotaro rather.

Also note that he uses the ORA ORA cry rather than DORA RA like Jotaro. 