Diamond Wa Kudakenai summary: SERIES 4: Diamond is Unbreakable Diamond is Unbreakable follows Josuke Higashikata and his good friend Koichi Hirose as they protect their town from the influx of Stand users. Jotaro Kujo arrives to warn Josuke about the Bow and Arrow a mysterious man is using to bring out a person's Stand abilities, but it is up to Josuke, Koichi and their allies to defeat those who would use their Stand abilities for evil - most notably Yoshikage Kira.