Since 2015, maximizing your character slots has been free in MapleSEA! Each account can have a total of 40 slots to accommodate for all the different jobs and classes in game. (With the exception of Pink Bean.) Here’s how you claim your character slots.
All you have to do is go to the character shop and click on the ‘Character Slot’ item!
Here’s a more detailed guide for those who are still unsure of what to do.
First, click on the cash shop button at the bottom right of your screen.
Select Game > More Slots
Click ‘Purchase‘ character slots. As you notice, it costs 0 Cash so it’s completely free!