From Shining Moon Wikipedia
Requires you to finish 5 Memorial Dungeons.
You have time until Monday 00:01 server time to finish these and hand it in at the Weekly Manager at @go exchange, which will then reward you a Costume Treasure and 5x Kachua's Secret Key
Costume Treasure, which contains a random costume headgear from Shining Moon.
Kachua's Secret Key contains a random item from Kachua Item List
List of instances that count towards the Weekly Quest.
|Weekly Quest Instances|
|Airship Assault||Bakonawa Lake||Bangungot Hospital||Bios Island||Buwaya Cave||Central Laboratory|
|Charleston Crisis||Devil's Tower||Endless Cellar||Endless Tower||Faceworm's Nest||Ghost Palace|
|Horror Toy Factory||Infinity Space||Last Room||Morse Cave||Nidhoggur's Nest||Nightmarish Jitterbug|
|Old Glast Heim (Normal Mode)||Old Glast Heim (Hard Mode)||Sara & Fenrir||Society Raid||Temple of the Demon God||Wolfchev's Laboratory|