This OVA is basically just an extra episode of the first season and it has has the same characters, animation, voice acting and music. It doesn't seem like this OVA adds anything to the story so you don't have to watch it if you only care about the main storyline. Instead it seems this was made to have girl's wear wedding dresses (that they conveniently had lying around at school). The story is about the teacher coming to the service club because she needs help writing something for a marriage event. She can't do this herself since she isn't married so she asks high schoolstudents instead. This somehow leads to a 'wife contest' with lots of comedy.

Since it's basically just another episode, you'll like this if you enjoyed the first season, you won't like this if you didn't like the first season.