This special is just pointless. The premise: the main character of the main series, Kotoura, briefly interviews the 5 main characters of the show, effectively providing a basic character synopsis for each. No matter which order you watch this special with the main show, it doesn't make sense: if you watch this before the show, it spoils the character dynamics and how they develop, and this provides nothing new for after you're finished watching.
For positives: some of the jokes are somewhat funny, I guess? Oh! It's less than 10 minutes long, so it at least won't waste a ton of your time!
Yeah, don't waste your time with this one.