What is Project Sekai?

Project Sekai Colorful Stage is a mobile rhythm gacha game featuring Hatsune Miku and other popular vocaloids (mascot characters for vocal synths) including Kagamine Len & Rin, Megurine Luka, MEIKO and KAITO. The games story aspect focuses on original characters split into 5 units ranging from an idol group to an underground music circle, all of which deal with various troubles and are developed over time through new stories and content released during events in the game. New cards featuring both these characters and the vocaloids are regularly released and can be obtained through the gacha system which is paid for either by earning gems through playing the rhthym game or purchasing them using real money (if you're not broke like me...). Currently the original Japanese version of the game is just over a year old and the English translated version has just been released for IOS and Android.