Arko

Arko, also known as Cave of the Stars (星の洞窟・ラキューオ, Hoshi no Dōkutsu Rakyūo), is an ethereal and space-like world where dead wizards are reborn as Stars, and is located in the Abyssal Realm. It is observed by an entity of Light known as Blackcurrant.

In Magical Vacation
After the students of Will-o'-Wisp acquire the Veil of Light, they must travel through Arko in order to get the Veil of Darkness from Blackcurrant. That way, they can pass through the Abyssal Corridor and track down Ganache and Candy.

The Veil of Light disguises the students as Stars, and they have to help the new Stars ascend in order to summon Blackcurrant. However, patrolling Clay Pots can see through the disguise, and will warp someone back to the Magic Bus if the party is right next to one.

Seirei

 * Beast Seirei 5
 * Give 30 Deparalyze Tails
 * Water Seirei 5
 * Give 10 Aqua Coins
 * Sound Seirei 5
 * Give 5 Vox Gold Coins (4 with the Small Ocarina and Arancia)
 * Light Seirei 5
 * Only joins if 3 or less Darkness Seirei have been recruited

Trivia

 * When the katakana of Rakyuo (ラキューオ) is reversed and adjusted, it spells Okra (オクラ). This is where Arko is derived from.