The Item Unknown quest requires you to find 10 “round, striped food objects”. This NieR Replicant Ver1.22 Item Unknown Guide will tell you what these mysterious striped food items are and how you can find some yourself, so you can complete the quest.
The Item Unknown side quest is a quest you can get in Facade. One of the people that live there tell you that they are unable to give you the name of the item as it’s one of the many rules their society lives by. As such, you’re given a basic description of “round, striped food objects”. With that in mind, you need to figure out and track down the items you need to complete the quest.
NieR Replicant Ver1.22 Item Unknown Guide
You need 10 Watermelons. Those are the “round, striped food objects” referred to by the NPC that gave you the quest. It is possible to find these in the wild and you can even grow them in your field back at your village but both of these processes are very long and time consuming.
Alternatively, you can simply buy the 10 Watermelons. You need to head to Facade and purchase them from the Grocers there. They cost a bit of gold but there’s plenty on offer with the side quests here, but if you do a lot of the other side quests, they often reward good amounts of Gold. Some can even give up to 10,000 Gold.
Once you have the 10 Melons, return to Facade to complete the quest.