Diamond is Unbreakable (CD)

The Diamond is Unbreakable Drama CD Collection (ダイヤモンドは砕けない ドラマCD) is a set of two original stories adapted from Diamond is Unbreakable that were released by David Production from 2016 to 2017 enclosed within the 6th and 13th volumes of the limited edition Blu-Ray. One having Josuke, Okuyasu and Koichi investigating a ghost story and the other one with Josuke and Koichi trying to help Okuyasu about a waitress he fell in love with.

Volumes
Drama CD Vol. 1: A Ghost Story from Budogaoka High (ドラマCD vol. 1 ぶどうヶ丘高校の怪談)

Drama CD Vol. 2: After-school Talk: At Café Deux Magots (ドラマCD vol. 2 放課後トーク カフェ ドゥ・メゴにて)