It's like Harry Potter if Harry was more studious and less whiny. They both begin the story in low positions, but Nic isn't willing to allow that to stop him from fulfilling his ambitions whether it's meeting the girl or learning as much as he can.
Too soon to see where the story will end up yet, but I like what's there so far. I'm especially grateful that the author doesn't lazily use brackets, parenthesis, or a chatroom style (e.g. Kyou: Hello world.) to denote who is speaking in his dialogue. The reader can easily pick out which character is speaking in this story from the context if it isn't stated by the narrator.
One nitpick I have is that when archaic English is used by the NPCs, spell incantations, and System popups it isn't too consistent and doesn't mesh well with the modern English that usually surrounds it.
As for Chacterization, there's only one main character so far, and most of the other minor characters that have shown up have all died off, although they do die spectacularly and in ways that progresses the plot. I have high hopes for his companions when they are fleshed out, but 6.5 has confused my take on the personality of his "Angel."
I did enjoy the April Fools prank even though I fell for it until the end.