Just watched the first episode, waiting for the next one to download. I'm not finished playing it too, a bit late playing it 'cause Persona 2 impression (It's hard playing it).
I think 10 years is a little bit too far.
And for Cameo Characters (until the latest episode)
-While Mitsuru herself has not made any sort of appearance in the anime sequel,a young girl bearing an uncanny resemblance to her is shown in the first episode bringing one of her fingers up much like the Main Character did near the end of the game.
-During the first episode of the anime, Akihiko's voice (or at least the same voice actor) can be heard speaking over the phone with RyÅ, one of the main characters. Whether or not the voice really is Akihiko's remains to be seen.
-Igor also makes an appearance in the anime sequel, meeting with the protagonist Shin Kanzato as a fortune teller. He tells Shin that they have met before in the Velvet Room.
I don't think it's a spoiler material, but just in case.