You can buy common non-weapon items from the Item Shop. This is one of the two default shops that you can access as soon as you start the game. It can be conveniently accessed from the activity selection or Battle Preparation screens.You can also access the shop on foot when you’re Exploring the Monastery.
The Item shop offers a wide variety of practical items that can help you in your battles. They have shields, recovery items, Seals, keys, etc. Similar to the Armory, there are items sold in limited amounts such as Intermediate Seals, Pure Water, or Iron Shields. The stock of these items are replenished each month.