‘The One with Unagi’

Season 6, Episode 17 -  Aired February 24, 2000

After Rachel and Phoebe take a self-defense class, Ross tries to teach them the art of "unagi". When Chandler and Monica's rescheduled Valentine's Day comes around, they have both forgotten to make each other gifts as promised. Elsewhere, Joey tries to earn some more money by joining a clinical research study on twins.