Barney is looking to learn more about Robin in How I Met Your Mother Season 5, Episode 3 titled, “Robin 101.”
He is taking classes in “Robin 101″ from her ex-boyfriend, Ted.
Barney’s suspicious actions have Robin thinking that he is cheating on her.
A Japanese man thinks Robin 101 is a legitimate class and asks Ted to let him audit and Ted agrees to this.
While the man’s grasp of English is suspect, his understanding of Robin 101 is not and when Robin confronts Ted and Barney about their doings, the man reveals what he has learned in class.