Super Planet‘s Sword Master Story is now running a collaboration event with Konosuba. As is usually the case, there will be a log in event until 31 May 2021 where you can get a 5-star Aqua, premium currency and a 5-star weapon and armour. The description provided by the Sword Master Story store page for the Konosuba collab is given as follows:
The great adventure of Kazuma’s group in Elgrad!
The first and last chance to meet the main characters of this popular animation is during the month of May!
▶ [New Characters] The popular characters Megumin, Aqua, Darkness are coming!
▶ [Special Costumes] Transform into Kazuma, Wiz, and Yun-Yun, just like in the original work!
▶ [Collab Dungeon] Defeat the monsters of Konosuba and get generous rewards!
… And, another ordeal is waiting for the SwordMaster!
▶ The Abyss is open!
Choose one of the three cards to get stats, and go to a higher level!
Time to become stronger with special items that can only be obtained from the Abyss!
If you fancy giving the game a shot just for the collab characters, you’ve got plenty of time to try it out in lieu of Konosuba Fantastic Days coming out in English, whenever that will be.