For me it was very interesting to get to see a little more of Furuya's daily routine and I can totally see why his character is so popular (well you might say I'm biased if you check my favorite characters and see him among them). Nad if I remember correctly I know there's another sequel to the series but other than that Furuya might be the only individual character who managed to get his own "spin off" even if it's releatively short (Kaito Kid doesn't really count since he existed even prior to DC and has his own big franchise).
A part of me wishes there would have been more episodes but then again I also get why they wouldn't include sensetive stuff reserved for the main series so I'll let it slide. All the characters stayed true to their nature and I loved it didn't feel like watching anything else. Furuya is very observant and talented but somehow I can't shake off the feeling that he is rather lonely. Especially after watching this.
The music is nice and fitting and the animation is very clean. Overall I'd recommend this mini-series to everyone who loves the main show and is at least fond of Furuya's character (up to this day I still don't know why I love him so much. Probably because he's a very complex character).
