There are two types of currency in Aika: Gold and Tcoins.
All gold is obtained by completing quests and selling items to NPCs. Gold may be acquired from other players through sales, trades, and raiding of a Nation's Altar.
Tcoins are purchased from T3FUN with one of the cash options listed on the website. Most Cash Shop items are tradable or giftable, very few items are restricted from trading in some form.