This would definately benefit from a different font, or no text at all. The style of the illustration seems very organic, and hand drawn, so you may try to create some text by hand. I like the concept of "lifetime friends" so you may want to push that more. Don't be afraid to throw a huge vertical LIFETIME FRIEND #1 down the side in a semi-messy script. I think it would sell the idea more, on this "series" atleast. Nice concept, good work.
PS- you should put this on a brown shirt, then I'd buy it. :)