Mahou Shoujo Ikusei Keikaku: Restart

The deadly game is back! Once again, sixteen Magical Girls have been assembled for a high-stakes challenge. Every three days, their Magical Phone pulls them into an RPG-like simulation where they have to work together to fight enemies, solve puzzles, and earn Magical Candy to advance. A staggering ten billion yen reward awaits them at the end—but only for the players who land the finishing blow. With such a tantalizing prize on the line, it's only a matter of time before the girls turn on each other—and if their hit points drop to zero, a game over will be the least of their worries… (Source: Mahou Shoujo Ikusei Keikaku Wiki, edited)