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.
Episodes
I Picked Up the Demon King
2011-01-09
I Became a Gang Leader with a Child
2011-01-16
Are There Any Strong, Ruthless Bastards Around?
2011-01-23
There Is One Second Before the Demon Lord's Floods Burst Forth
2011-01-30
Money can buy anything
2011-02-06
Toys Have Arrived from the Demon World / We Played Doctor
2011-02-13
The Demon Lord makes his Park Debut
2011-02-20
We Meet Again
2011-02-27
Love is a Hurricane
2011-03-06
A Disciple Was Gained
2011-03-27
There was Something Money Could not Buy
2011-04-03
I Won't Let You Sleep Tonight
2011-04-10
Baby Beel's Assessment Test / Hilda: Dear Great Demon Lord
2011-04-17
Is There a Special Move?
2011-04-24
The Delinquents Have Changed Into Swimsuits
2011-05-01
You're Not a Bad Specimen of a Man
2011-05-08
How About Some Demon World Homework?
2011-05-15
I Quit being the Baby on Back Brawler
2011-05-22
The Doctor Has Arrived
2011-05-29
Everyone Assemble
2011-06-05
Who Do You Think Is Ishiyama's Strongest?
2011-06-12
Secluded Mountain Training
2011-06-19
You Kidding Me? The Demon World
2011-06-26
Welcome Back, Demon World!
2011-07-03
New Semester Started
2011-07-10
May I Call You Brother?
2011-07-17
Called the Magical Girl
2011-07-24
Let's All Get Physicals
2011-07-31
What Are the 6 Holy Knights?
2011-08-07
Who Could the 6 Holy Knights Be?
2011-08-14
No Conclusion Was Reached!
2011-08-28
What Has the Transfer Girl Done?
2011-09-04
There Are Wounds in the Past
2011-09-11
Maids Run Amok
2011-09-18
Time for the Game to Begin!
2011-09-25
The Victory has Finally Arrived
2011-10-02
This Man is a Teacher
2011-10-09
The Sibling Rivalry Has Begun
2011-10-16
His Brother Was a Crybaby
2011-10-23
No Shirt, No Shoes, No Assassins
2011-10-30
On the Brink! What'll We Do?
2011-11-06
It's Time to Train
2011-11-13
Where Did the Older Brother Disappear To?
2011-11-20
I Have to Get Stronger
2011-11-27
There's One Day and 1 Hour Left Until the Game
2011-12-04
Burn, Super Combination!
2011-12-11
Sorry to Have Kept You Waiting
2011-12-18
I'm His Parent
2011-12-25
Beelzebub's New Year's Special! Beelbeel Journey to the West!
2012-01-08
Today I'm Different on the Inside
2012-01-15
Komainu-sama is Watching You
2012-01-22
And Then There Were No Delinquents
2012-01-29
Baby Beel's First Conquest / Furuichi Falls in Love
2012-02-05
Black Baby Beel Grows Up!
2012-02-12
I Have Lost My Pompadour / The Great Demon Lord Has Come
2012-02-19
Are You a Traitor? / Is This a Job for Men?
2012-02-26
Won't You Eat a Manju? / Won't You Get in a Mixed Bath?
2012-03-04
Akumano Academy is Open!
2012-03-11
We're the Strongest!
2012-03-18
I Won't Say Goodbye
2012-03-25
Voice Cast
