Shiranpuri is a one episode anime but don´t let that discourage you or else you might miss this little fine gem here
For one episode it has a better narrative (beginning, middle and ending) compared to many 12 episodes anime shows which often concludes into nothing.
Shiranpuri is about bullying, it isn´t really something new because this topic is already explored through many other media and in various ways.
But what I like about this one is its mores realistic approach and being a point of view for a bystander, not the one who is being bullied:
I can hardly see any reason to skip this one especially because of its unique but quite well made animation, good voice acting, good plot phasing and it being a whole story itself.
It doesn´t need more than one episode because it knows what it wants and does it.