Meet the Bank NPC:
Inevitably, as any MMORPG player learns quickly, you'll acquire many items that will be useful later but do not want taking up inventory space. Thus speak to this guy and he'll store everything until you need it. Players store etherites, crafting supplies, brooches, ARs, energy converters, costumes, and many other items.
Storage space matches inventory. At max, it is 6x8 (6 across, 8 down) per bank page. It can go up to 8 pages, though only packrat-minded players that store everything will likely use it all. To store items, either click-and-drag or (preferred for speed) double-click items to store or retrieve.
() Dzenai (often called "zenny" in-game) can also be stored. Simply click the "deposit" button, use in-game or keyboard numbers to select amount, and either click the "ok" button or hit enter. Players who use alts chiefly to put items on BSW's market use this. Also, note that withdrawal and deposit amounts max out at available zenny; in other words, it is impossible to "create" more money in-game.
Ordon, like your inventory, separates items into the categories of Normal, Fashion, and Premium. New players will find inventory is limited, though certain in-game events will offer warehouse expansion tickets that unlock additional space; Fashion and Premium are fully unlocked, so require no such tokens.
Warehouse expansion tickets are easy. Simply click the below icon, confirm, and done. Each ticket unlocks 12 additional slots:
Players who wish to expand their bank space will want to play the main quest line through Ruined Fortress. One of the rewards is 4 Warehouse Expansion Tickets, enough to unlock an additional page of storage.
Note that tickets are used one at a time. Only the one highlighted with green can be unlocked with available ticket. When orange: will not unlock until the preceding ones are done. So if I want to unlock page 7 of my bank, but page 6 has 2 expansion slots left, those 2 must be unlocked before I can unlock the 7th page.
Certain items cannot be banked. They are denoted with a red "Storing not possible" in item description. Any attempt to bank will trigger a pop-up window stating said item cannot be banked.
Crafting supplies such as Star Platinum and Merged Dimension Light have a banking amount of 999 per slot. Certain items like Hysteria Stone and Glutton Coins have a limit of 9999 per slot. It is unclear if this is intentional or developer oversight.