Field Trip Arc

The Okinawa arc is the seventh story arc in Beelzebub. It consists of Chapters 148 to ongoing, beginning with the introduction of Kanzaki's niece, Futaba. Afterwards, the arc then transitions to Okinawa, Japan where the students of Ishiyama and Saint Ishiyama are currently taking their field trip. In the new city, they find themselves at odds with a local school called South Chinpira High School.

Synopsis
Spoiler warning: Plot and/or ending details follow.

Babysitting
Hajime is lounging on the couch at his home, reading a magazine. His little niece starts pestering him to play with her. He ignores his niece and continues to relax. Hajime thinks to himself about how a "mischievous little ghost" has been haunting him since the Akumano Academy invasion.

In the meantime, Hilda has prepared dozens of croquettes for Oga but he refuses to eat them due to their unpleasant appearance. Hilda says that it's a token of thanks to Oga since he's saved her before several times in the past. He continues to refuse the croquettes and Hilda expresses her anger at him for insulting her cooking. They have an argument about Hilda's cooking which is quickly dissolved when Oga's family returns to the house. His family, mainly Misaki, is disappointed in the return of Hilda's memories. Oga's Mother tries to explain to Hilda about when she had amnesia but the Demon Maid doesn't remember anything from it. Oga feels relieved somewhat, as he thinks that she would've done something drastic if she remembered anything about her past. Hilda turns to Baby Beel and notices how much he's "changed" since they last met before hugging him affectionately (not wanting to "lose" to her former, amnesiac self).

Furuichi and Lamia talk outside about Hilda's memories returning. Lamia theorizes that Hilda's former, innocent self was actually another side of her and that it may come back in the future. She then tells Furuichi that she's hungry and they walk together. Oga decides to go out to the corner store with Baby Beel and Hilda accompanies him. Oga asks if she's always going to be around him and Baby Beel, to which Hilda answers, and reminds him that he chose to become her master's parent. Upon hearing this, Oga says that he's not going to let Baby Beel destroy humanity and Hilda replies by saying that, because she serves Baby Beel, she won't destroy humanity if he decides not to do so. She adds by saying that she wants the Demon Lord to be the best that there is and how Oga is only one who can help him.

The next morning at the school, a morbid-looking Kanzaki decides to talk to Oga and asks if he can babysit his niece, whom he was instructed by his family to look after. When Oga refuses, he angrily says that Oga needs to repay him for helping save Hilda, but Hilda insists that he should help because she sees Kanzaki as another "peasant under Baby Beel's rule". Nevertheless, Oga goes and brings a reluctant Furuichi to help.

Oga is quite stunned by how extravagant Hajime's home is, mainly with the underlings that follow him. Hajime leads Oga's group inside his house, which also serves as headquarters for a Yakuza-based group that Hajime's father Mugen heads. Hilda initially has conflicts with Mugen when he claims that his granddaughter Futaba is cuter than Baby Beel. Hajime tells his father not to be embarrassing himself and even full-out tells him how Futaba doesn't really like him. When Mugen starts crying out in confusion, a young girl kicks him in the back for being so loud and yells at Hajime for making her hide from her grandfather too long. Hajime says that the girl acts this way because Mugen spoils her and this is further proven when she asks one of Mugen's underlings to act like a horse for her to ride on. Oga, Hilda, and Furuichi all note how she's actually more bratty than spoiled. They go to Hajime's room with him and the young girl is properly introduced as Futaba. After some insistence from the others, Furuichi tries reasoning with Futaba by pointing out her flaws but she couldn't care in the slightest. Oga then does the talking and starts off with Futaba's actual strength. He asks if she can back-up the claim that she does the bossing around with her underlings. This draws Futaba's interest but the topic is quickly brushed off when Oga claims himself to be the strongest person she'll ever meet.

Hilda then uses Baby Beel to talk to Futaba. However, Futaba becomes interested in Baby Beel and makes him her lackey. Because he cannot keep himself composed because Futaba is a girl, Baby Beel cannot seem to refuse her even with just random babbling.

Futaba decides to take Baby Beel with her, bringing along the others with him. Hilda starts scolding the Demon Lord for listening and obeying Futaba, but then Futaba starts insulting Hilda by calling her an "old hag". Baby Beel tries to play peace-maker between the two but to no avail. Eventually, Futaba decides to have a little showdown at the river and brings the gang with her. Her choice of battle is revealed to be a round of stone skipping. She manages to score five skips but Oga cheats and uses Demonic magic to skip his rock to the other side of the river.

Futaba then gets Kanzaki to throw the rocks for her and he decides to participate, telling Oga that he's not the only person who went through Saotome's training. Kanzaki, using elements of nature around him, skips the rock and it starts making way for the other side of the river, much to the others' shock. But then a catfish gets in the way and Oga wins the round. But Futaba won't admit defeat and even starts crying. As Oga keeps taunting her, Hajime punches him for making Futaba cry. Oga then says that he leaves everything else to Hajime, confusing him, and leaves with the others.