The mark on Oga's arm goes back to its small size, much to the chagrin of Hildegarde who destroys his games console. She brings a play room for Beelzebub to play in, but upon building it, it turns out to be a magical cage that both she and Oga get stuck inside. The only way to get out is to have Beelzebub solve a block puzzle toy, but he just ends up breaking it. Frustrated, Oga utilises his Zebel power to punch his way out, though it makes his mark grow big again. Rummaging through a bag of demon world toys, Beelzebub opens a chest that transforms Oga and Takayuki into nurses, which can only be reverted by helping Beelzebub play Doctor. Oga decides to use the opportunity to try and do good deeds and get rid of his mark, though has trouble handling the demonic medical supplies. After some failed attempts at treating some of the students, they change back after discovering an actually useful tool on Beelzebub's costume, but accidentally triggers an explosive that negates all the work Oga did getting his mark down to size.
Tandis qu’Oga tente de rester sage pour gommer sa Belzemarque, Hildegarde rapporte des Enfers quelques jouets originaux pour distraire Beelzebub. Au programme : cage à monstres, boîte à formes et panoplie du docteur (et ses infirmières)...
Baby Bell vuol giocare al dottore! Legger... ahem, ascoltare attentamente le istruzioni e le modalità d'uso.
La marca del brazo de Oga va regresando a su tamaño pequeño mientras Oga se dedica a matar el tiempo jugado a videojuegos, por lo que Hilda decide romperle todas sus consolas y traer una habitación de juegos para Beelzebub desde el Mundo Demoniaco. Pero estos juguetes serán más peligrosos de lo que a simple vista parecen y meterán en problemas a Oga y Takayuki.
