When starting out in Lunia it's hard to tell which items you're going to end up wanting. This guide is to help new players learn about some of the more useful items to keep.

Fortification Items

Fortification items are used to upgrade equipment.

You can find them from Loose Boxes or the Bonus Box on the right when you clear a stage. Fortification items can also be obtained through extraction of equipment in the square.
Elemental Stones

Elemental stones are used in crafting to make Shining Powder, Stones of Restoration, or some of the best high level equipment.

You can find elemental stones as the stage reward for boss stages or from the Bonus Box on the right when you clear a stage.
Fish

Fish are required to complete the daily fishing quests. Fish can also be traded in, when you have enough, for some valuable items at the Fishing Master.

To get Lunia Gold fish, you need to fish. See the Fishing Guide to learn how.
Colored Beads

Beads can be traded in for some valuable items at Duran in the square.

You can get Lunia Gold beads by completing the daily fishing quests at Duran.
Gemstones

Gemstones are used in crafting for some of the best equipment in the game.

You can get gemstones as the stage clear reward for bosses or from the Bonus Box on the left when you clear a stage.
Raid Craft Items

Raid craft items are used to craft the equipment set from specific raids.

You can find these items throughout raids and as stage clear rewards for raids.
Raid Keys

Raid keys are for getting Lunia Gold into various raids. It's good to keep stacks of keys for when your friends or guild want to go raiding.

Each key is found in a different stage. As you find them, open the boxes and store your extras.
Finding Enough Room

Alternate characters can be created to deal with the item space limits. For example, you can have your fortification character that you send all your fortification items to, and a elemental stone character that gets all your elemental stones.

To transfer items between your characters you can use the mail system. If your guild has stamps in it's store this process becomes trival.