If you have seen Acchi Kocchi the main anime already this is an extra episode, same type of content, fun, cute and inocent, i would recommend it if you have watched already the main anime and want some more of Tsumiki, Io and there friends, personally i enjoyed the series so this episode was a new spoon of the same taste, Acchi Kocchi may not have the best Art, Sound or Story...yet the main focus is on the cuteness and enjoyment of it all.
To make it short:
If you liked the main anime this episode would be an extra presentation of the same.
If you have not
seen this anime, you could either watch it first and decide by this episode if the series is for you, or watch the series first and then approach this ova again.