Players can unlock characters in Otherworld by getting shards. For the moment, shards are only available by top-up in the Otherworld shop.
Each Otherworld chest can offer you between 1 to 50 Natsu shards, Starsand, Otherworld Currency and Voucher for the Shopping Street.
Otherworld characters have their own exclusive skills. Once you unlock a character, you can equip special skills in the Astrolabe tab (note that if you remove or switch characters, skills will be reset and you will have to set skills again).
Profitable Growth Event
Once you unlock Natsu, advance him through Star-up to get 50 free shards.