Obligation (Shukumei 宿命) is the eleventh episode of the Accel World Anime. It aired June 22nd 2012 in Japan.
Both Haruyuki and Yuniko realize that Yellow Radio was the one responsible for the fifth Chrome Disaster, using a loophole in the non-aggression treaty as an excuse to eliminate her and reach Level 10. He then takes out Kuroyukihime by displaying a recording of herself beheading Red Rider, the first Red King, demoralizing her enough that she faints. Haru, Yuniko and Takumu are then forced to endure the onslaught from the Yellow Legion. During the battle, Takumu sacrifices himself to buy the others time. As the Yellow Legion starts to overwhelm them, Haru urges Kuroyukihime to wake up and she does. Kuroyukihime does battle with Yellow Radio and just as they charge up their killer moves, Yellow Radio is impaled through the back by Chrome Disaster.