These are just short little stories that show a bit more of the character's starting in this show in a funny way and then near the end of the main series with just extra, or alternate scenes from the show.
Since it's after the real episode, it's always fun to watch and isn't a hassle.
Be aware, it will take the serious out of the moment. Overall its cute.
This "special" is at the end of each episode and doesn't really contain that much stuff.
Most of the time its just Mur Mur talking with the characters in the anime. Sometimes, but rarely it does give some extra background info about the characters (ie. where they lived etc.) but its not necessary.
Its comedic relief (which i don't like), which breaks the suspense.
Should You Watch It?
Yes if you like comedic relief, Mur Mur or just have some extra time. If you watch 1 episode each day, breaking the suspense doesn't really matter.
No if you dislike comedic relief, hate Mur Mur, or is short on time.
If you continuously watch episode after episode of the anime, you probably don't want to ruin the suspense, so you should not watch it.
Personally, I kinda have a love-hate relationship with Murmur. In these little snippets (usually featured at the end of the episode) she was funny and kinda adorable, but in the real show, I found her annoying and intolerable. I honestly really hated her. However, these clips helped me get to know the characters, so I liked then.
There's not really a storyline, if I'm being honest.
Next off, the animation was unique. Sometimes it was the regular, once it was
stop motion, etc. The clips all had different things and were pretty entertaining.
The sound was alright, though sometimes it felt odd and I wasn't
really digging the music in the background.
It really gave us insight into a lot of the characters that seemed so violent in their screen time, especially since it would've been hard to disclose that information in the actual show without it seeming awkward.
Overall, it was pretty enjoyable.
I would recommend this if you: like the Future Diary characters, want to know more about the characters/their backstories, like Murmur, like anime shorts
I would NOT recommend this if you: like keeping a continuous violent/suspenseful aura about you as you watch this, hate Murmur, don't really care about character backstories