This shows supporting characters acting with out Tsukimi or Kuranosuke. The jokes are average, except the 4 episode. The cat and the car had me dead. I suggest watching episodes 1-3 after episode 2 or 3 and Episode 4 after Shuu is introduced in the main series. It doesn't give spoilers. It does give more characterization to the sisterhood. This can obviously be watched after completing the series. But because it doesn't contribute to the story in anyway, it won't help fill the void of finishing the series. Even without a plot, it is still a fun watch. There are good jokes and they areonly 5 minutes long. It is definite worth to watch if you love a certain character and want to see more of them. Shuu, they didn't give you enough screen time! Cries in lack of second season.
Clearly this is for those who have watched or are watching the main kuragehime series.