Tenbatsu Angel Rabbie☆ Episode OVA

Long years after a war destroys most of the earth, Lasty Farson is one of the "angels" sent to points in history to set things right. Lasty is hopelessly clumsy and inept, but once she transforms into Angel Rabbie, she's the best there is. On her first day as a debut angel, she's late, but she is sent to earth and ends up battling old robots from the war--a tall order for a rookie angel.

(Source: Anime News Network)