Jotaro's Disc is actually 1/2 items needed to obtain Made In Heaven. You will also need DEO's Bone to obtain Made In Heaven.
How to Obtain
Jotaro's Disc is an item you can obtain after defeating JOE (Jotaro Part 6). There is a small percent chance of it actually dropping, so it will be pretty hard for you to complete the Journey. (Especially when Joe Kujoe is a hard NPC to defeat)
- Joe's Disc cannot be sold
- Joe's Disc cannot be dropped
- Joe's Disc is an important item along with DIO's Bone to obtaining Made In Heaven.
- You might need a group of people to help you defeat Joe.