Episode 20: History
This episode is basically a recap episode. The frameworkd for it is a radio show. Aine is shown at home doing her homework, and Λucifer is the guest on the radio show she is listening to. They start talking about their History, and the show flashes back to all the stuff that happened in the previous 19 episodes. At the end, they tell everyone to look for their debut single, and then Sakuya says a special message to the audience. We then see that Aine is no longer listening because she has fallen asleep at her desk ^_^;