Monster Strike

Monster Strike (モンスターストライク) is a free mobile game for and  developed by. On July 10, 2022, a collaboration with the anime JoJo's Bizarre Adventure: Stone Ocean was announced. The collaboration began on July 15, 2022 and ended on August 2, 2022.

Summary
Monster Strike is a mobile game where players must collect and enhance monsters/characters to place them in battles. The game was first launched in 2013 for iOS and Android and features puzzle gameplay and online multiplayer. The game is known for releasing crossover content with famous franchises, including and. Some of their anime collaborations in 2022 included, , and.

In August 2017, Monster Strike shut down the servers for the English version of their game.

Stone Ocean Collaboration
On July 10, 2022, XFLAG announced a collaboration between the anime JoJo's Bizarre Adventure: Stone Ocean and their mobile game Monster Strike that began on July 15, 2022, for a limited time. By purchasing the JoJo’s Bizarre Adventure: Stone Ocean collaboration starter pack, players could get an exclusive unit featuring both Jolyne and Jotaro. This unit was limited to one per person and was also only available from July 15, 2022, to August 2, 2022. The collaboration also featured five limited quest events against minor villains from the anime. These include Lang Rangler, Thunder McQueen, Gwess, Johngalli A., and Miraschon.

On July 14, 2022, it was announced that the character Enrico Pucci and the guardian beast Stone Free would be obtainable in the game from July 17, 2022 to August 2, 2022 by completing quests in-game. It was also announced that the collaboration would introduce a "Dollar" currency system could be earned from completing quests during the collaboration period. Players would then be able to use these Dollars on "G.D. St. Prison Missions" and redeem unique items from the "G.D. Store" until August 4, 2022. Completing these missions rewarded the player with a unit featuring Jolyne, Ermes and F.F., as well as unlocking various stickers including Emporio, Gwess, Pi-chan, Charlotte, and Pucci. Once all missions were completed, the player was rewarded with the "Jolyne’s Butterfly" medal.

On July 21, 2022, XFLAG made a second update to their collaboration, announcing a new unit featuring Emporio, Weather and Anasui that would be available from July 22, 2022, to August 2, 2022. The unit would be obtainable by spending 5 Dollars to make a phone call with your "mother" at G.D. st. Prison. Once a phone call was made, the player would've had to wait 24 hours before they were allowed to make another. Alternatively, players could spend an additional 10 Dollars to reduce the wait time. The update also introduced a system where players could earn "Ora Ora Points" as a log-in bonus, or by clearing the "Ora Ora Rush" collaboration quest. Players could then choose to spend their points on either Jotaro or Jolyne to get different rewards. On July 29, 2022, the option to call the Speedwagon Foundation was added to the phone booth, which unlocked a hidden "Operation Savage Garden" boss quest against Pucci. Beating the quest rewarded the player with the "Savage Garden" medal.