I love the potential of this game; combining the prompt—to tell a story with no prep—with two randomization effects to motivate and narrow your creativity is really smart. 

While I'm not familiar with The Canterbury Tales, the setting seems like it would also bring a lot of atmosphere and mood to the game. In such a short space, this is a suggestive, poignant setup.

It's also a very, very cool double-layering to both play a character & have that character telling a story to others. I'd love to see how something like this shakes out in actual play!