From Sonic Dimension:
More pics at the link above.The following comes from using an online translator:
- Two new human characters: Chris (seen in the above pic) and Danny
- Possibly a different storyline from the video games
- Chris saves Sonic from drowning in a pool when they first meet
There's more stuff on the page, but I'm not sure of the accuracy so click the link above and judge for yourself what other info you'll trust from the translator.
Source: Sonic Dimension | 