I love the idea (not the coffee addiction part :3) but having your chibi-sona express all the jitteriness induced by coffee.

You may find me to be a bit literal, but I put it all in good fun and insightfulness for your benefit as an artist. Something I found a little incongruous is the shocked expression. Ya know, I assume if you are an addict, you would know the effects of what you just ingested. So, a slight change in expression from shock to "happy-happy, joyful craziness" expression would probably suit your intentions much more nicely. ^_^

Nice work Nyoku!