Beelzebub - Season 1 Episode 50

Due to the after effects of Super Milk Time, Baby Beel and Oga have swapped bodies. In order to return things back to normal, they try to look for Saotome-Sensei to see if he knows how to, however they are continuously disrupted by everyone else from the academy trying to start a fight with Oga (who is currently Baby Beel). Eventually, Baby Beel runs away after being drawn to a smell, and Hilda, Furuichi and Oga try to catch him, where they find him attached to Aoi. After hugging Aoi, BabyBeel runs off once again and so Hilda and Aoi have a match to see who can catch Baby Beel. Although at the end BabyBeel chooses Aoi over Hilda after she shows some of her new demon magic from training. Not long after, Aoi and Hilda attack Oga(Baby Beel) when fighting over him, and just before they hit him Oga and BabyBeel return to normal, leaving Oga being severely hurt by the two and BabyBeel perfectly fine. Saotome-sensei then comes to school the day after.