Ep. 1: The Takanashi siblings are up to a few things: Sora and Raika try to play a prank on Miu; Miu dresses up her neighbour, Shiori; and Hina wanders into town on her own.
Source: ANN
Ep 2.: 4 years pass after the beginning of the story. Shingo and Yuri got one day-off from Heaven to visit Yuuta and girls.
Note: Bundled with 13th and 18th light novel volumes.