This is looking great!
Few things that leapt out to me:
There’s a grey/shadow region on the blue (chuu) totoro’s tummy that is a bit unappealing.
See if you can get Totoro’s mouth a little better defined so it reads more clearly.
The reflections in the pupil of Totoro’s left eye (screen right) are slightly distracting, the specular is perfect but the additional reflections deaden his expression a little.
Finally, I think it would be really nice if the rim light picking out the edge of the chibi and chuu totoro was as strong on Totoro himself.
All tiny things but thought I’d share none the less.
Great job!
