Sega has announced a new Hatsune Miku smartphone game project under the title “Project Sekai” developed by Colorful Palette, a new studio by Craft Egg (BanG Dream! Girls Band Party!), with an immediate launch of the teaser site upon the announcement. Not much is known about the game for now, but the target platforms are known to be both iOS and Android. Stay tuned.
Project Sekai Twitter
https://twitter.com/pj_sekai
Teaser Site
http://miku.sega.jp/pjsekai/teaser/