This OVA is literally an episode 13 of the main anime. Same art style, same VA, same everything. If you want an extra laughing stock to consume, then this is the perfect episode to watch. Its filled to the brim with funny interaction between the club members, a stress relief i could say. There is also some secret trivia revealed about the characters.
The main anime have a beautiful ending with everything explained. So this OVA served as a filler episode. There isn't much going on, but it is worth a watch so you know deeper about every characters relationship. Because this whole episode plot is revolving around Christmas party, that mean there is a lot of heavy romance scene. Even though its just a bonus episode, I really enjoy it. Have a great time watching this smiling nonstop. Thank you for reading my review.