What's the Rokkisei?

is episode 29 of the Beelzebub anime.

Summary
After being shocked early in the morning by Baby Beel, Oga's enthusiasm to find someone new to pass Beel onto is temporarily reborn, and upon hearing rumors of six students who excel both academically and athletically, he goes off searching for these six in the hopes that they will impress Baby Beel. Oga, accompanied by Aoi, goes searching for Kazuya to get more information about the 6 Holy Knights. Meanwhile, Furuichi runs into an old friend, Miki. He warns Furuichi to stop Oga getting involved with the six, and tells him that the six wear badges to identify them as Holy Knights, before promptly revealing himself to be one of them. Oga finds Azusa while looking for Kazuya, and is quickly interrupted when two of the Knights show up, revealing themselves to be Alex and Sakaki. Sakaki tests Aoi's strength first by attacking her with a wooden sword, while she only has a ruler she borrowed from Azusa to defend herself with. Aoi cuts the tip of Sakaki's sword off during his attack, proving herself to be the more skilled swordsman. Oga refuses to fight his opponent, Alex, and instead quizzes him while attempting to dodge his attacks. Alex gives up when he realizes Oga is not taking the fight seriously, and the two knights leave the scene.