Where Might My Brother Have Disappeared to?
Lamia asks Fruichi to find Baby Beel's brother but when they went to the game center, they find Kanzaki,Himekawa, and Yuko. Furuichi asks them for help. Meanwhile Aoi and Oga went for training to be strong.
Aired 20/11/2011EP 43 - Where Might My Brother Have Disappeared to?

2011
Beelzebub
Oga Tatsumi is a first year student in Ishiyama High, a notorious school for delinquents. One day he sees a man floating by, and the man suddenly splits in half to reveal a baby boy inside!
(Source: Crunchyroll)