The One with Unagi

Background

Rachel and Phoebe take self-defense classes. Ross, who previously practiced karate, stages a surprise mock attack to convince them they lack unagi, supposedly a state of "total awareness", though unagi is Japanese for eel. Chandler and Monica celebrate Valentine's Day several days late, but when they forget to make each other homemade gifts, Monica gives Chandler one of Phoebe's "sock bunnies". Chandler finds a mixtape in the closet and gives it to Monica, unaware it was a present from Janice, complete with her recorded voice. When Joey applies for an identical twin research project that pays $2,000, he recruits someone to play his "twin".