The Higurashi series is one of my favorites all time, but Kira is a 10 year anniversary celebration and not to be taken very seriously. Even still, I was mightily disappointed by the first episode alone which is nothing but unapologetically blatant fan-service. Episodes two and three were more of what I was expecting, but they still felt somewhat mediocre and pandering, mostly due to the bad taste episode one had left in my mouth. Episode four, however, is a saving grace. It brings back the charm of Hinamizawa, and the peace that has settled on the town since the events of the previous seasons. Episode four is a fantastic sendoff and farewell to a great series.
Personally, I could have done without the first three episodes of Kira with the fourth being the only episode, but fans that have watched through the previous three seasons probably owe it to themselves to sit through it and watch all of them. If you are highly adverse to fan-service I recommend skipping the first episode. Trust me, you won't be missing out on anything by doing so. Episode four,however, is a must for any fans that have made it this far.
