Episode 43: Gensokyo Gaijin, part 11 of 13
Well... seeing as Yaiba is kinda a samurai, his statement makes a bit of sense... but not too much, since he is a corrupted samurai. The "Son, I'm dissapoint" meme would really fit here.
And Yukari has a lot to explain here. :V
Original Spanish comic: Las paridas de la guarida #43, parte 11