Kuma Kuma Kuma Bear

Fifteen-year-old Yuna prefers staying home and obsessively playing her favorite VRMMO game to doing anything else, including going to school. When a strange new update gives her a one-of-a-kind bear outfit that comes with overpowered abilities, Yuna is torn: the outfit is unbearably cute, but too embarrassing to wear in-game. But then she suddenly finds herself transported into the world of the game, facing down monsters and magic for real, and the bear suit becomes her best weapon. (from manga)