I don't think I quite knew how much I loved this series until I finished it.
This is gonna be a short one to tell you guys how wonderful this final episode was. So, this episode will simply wrap up everything that we've seen so far. There were a few unanswered questions at the end of the third season, and this hour-long special answered all of them. It had an interesting and silly way to tell part of the story that I really liked, and it made it feel somewhat like a grand adventure. The rest of the episode was just good, heartwarming fun. The characters developed even more in this episode in a couple of ways. I was glad to see certain characters being true to their feelings, even beyond the main two characters; so, even in an extra episode like this, there's still changes happening.
I'm really glad I watched this series. It was rough going at first with the lack of character progression and storytelling, but by the end I was completely in love with these characters and everything surrounding them. It made me really happy. Please do give this anime a go if you haven't yet. It'll surprise you.