Oga becomes filled with anger and tells him not to laugh at her. From the experience, she concludes that the person is responsible for Nasu's immense power and speculates that there is another party involved. Oga remarks that Hilda would have destroyed the gymnasium and that Saotome was going to get killed. She often knows more about the current situation than any of the other protagonists and is easily able to manipulate others into doing what she sees best. 7:18. A small, violent conversation turns on between the two women with amnesic Hilda thinking that Kunieda was her husband's wife.

Pillar Head Salamander decides to use his Lost Priminece, a fire which burns all of the person's memories. Faking disappointment, Oga tells Beel that Hilda won't return to normal anymore. They met different people: the Red Tails, Himekawa, Kanzaki, the Six Holy Knights, and others. In one chapter, she was shown wearing a yukata while playing with fireworks along with Lamia. The fight starts with the two pairs jumping high above – the two men start fighting in the same way the two babies did, while the two women start a verbal war. Hilda and Oga make a plan to rescue her.

Shiroyama and Natsume help Kanzaki go through intense "BoB" training.Furuichi is called back from a resort on a tropical island where he was vacationing with his family to go to the public pool with Oga. In the beginning, Oga's family easily welcomed Hilda and Beel into their family, and Misaki was shocked at how big her breasts were. Upon arguing with Kunieda regarding the seating arrangement, she already gained the fame of being the wife and Kunieda being the mistress. She enjoys teasing and tormenting Oga, frequently making snide remarks about his intelligence and (in her own mind) poor parenting skills.

She becomes scared that if she regains her memories, she will lose the feelings of happiness from that moment. According to Beelzebub's demon maidservant Hildegarde (Hilda), if he moves farther than 15 meters away from his human parent Oga, the electric shock will reach lethal levels. She defeated the three wet nurses in a blink of an eye. Hilda often looks down on him and never hesitates to mock him. Then Hilda takes Oga's wrist to check the Zebul Spell, and Oga finds out that she got caught on purpose to measure Himekawa's strength. Hilda then prepares to leave for the After a certain number of days, Hilda contacts her master from the Despite the fact that she is naturally just as fast as strong she is as a demon, Hilda rides a giant bird-like being named Hilda's relationship with Oga is one of the most complex relationships of the series. When she got amnesia, her personality became significantly more innocent. Because of the sheer strength and speed of the ball, everyone became intimidated until Kunieda Aoi volunteers to do it. She is also the main female protagonist of the series. Oga retorts, saying that Santa would never bring anything that big in his bag and that the only thing Santa would have are mechanical pencils.

While Hilda is reading a book and having tea, she is inquired about Baby Beel's age from Oga. Hilda asks what Beel would like for Christmas - which she claims is the Gorgonzola. They soon discovered that the only way for her to get her memories back, as described by Salamander, is to get a kiss from her "Prince Charming". Hilda was shocked and did not speak from that point on.

Hilda is already considered as Oga's apparent bride/wife by the whole Ishiyama school and his family, gaining her nicknames such as "Oga's bride", "Wife", or "Wifey". She commonly calls Oga a "damn fool", though recently the term seems to have become less of an insult, and more of an affectionate gesture. Oga holds her shoulders and told her with a grim face that the Hilda they know was a violent and merciless woman, taking off all hope for her to regain her memories back. When Yolda, Oga, and Furuichi watched the tape, they see some of the Pillars by the river trying to catch crayfish.

She was able to defeat Kunieda Aoi, one of Ishiyama's As she is still a non-contracted demon, it is conceivable that Hilda's potential full strength has still not been shown.