Keeper of the Cosmos

Keeper of the Cosmos -
A dimensional riff has occurred, and in a desperate attempt to recover itself, it gave the ability to open and close portals to a pair of humans.
A teenage fangirl and, ironically, her main idol (who may or may not also be her crush). Just thinking of their favorite fictional characters or celebrities causes them to appear in the girl's closet, which has been turned into a safe haven.
It's up to them to fix the rips in the dimensions and close potentially dangerous portals with the help of the people they've summoned. Oh, and make sure no one gets killed in the process.