S1·E9 Love is a Hurricane

The delinquent group, MK-5, come to confront Oga, but are promptly beaten by him and Hildegarde, who catches the attention of a smitten Aoi. As Aoi's right hand ladies, Chiaki Tanimura and Nene Oomura confront Oga, Hildegarde, who had heard from Oga about his plans to dump Beelzebub onto Aoi, challenges her to a fight to test her strength. When Aoi returns to find Chiaki and Nene injured, she assumes Oga is responsible and confronts him in a fight. In actuality, Chiaki and Nene were attacked by MK-5, under the orders of Miwa, who desires the title of Queen. Shintarou helps Nene get to Aoi to tell her the truth, but when Miwa makes his move, Oga promptly beats him up. Afterward, Aoi is once again baffled by Oga trying to give her Beelzebub, explaining that he's forced to raise him because of Hildegarde. Later, Aoi decides to quit the Red Tails and put Nene in charge, feeling that she is no longer able to serve as their leader.