Hildegarde

Hildegarde known as Hilda for short, is a character from Beelzebub.

Chapter 20
She mentions that she and Kaiser de Emperana Beelzebub IV are going to take a Bath when they get home (to Tatsumi Oga's house) which happens Off Screen.

Episode 12
People mishear a story and ends up being told throughout all of Ishiyama that Hilda and Tatsumi Oga have been taking Baths together which the thought ends up making Aoi Kunieda angry.

Episode 56
She attempts to take a Bath with Kaiser de Emperana Beelzebub IV but he ignores her along with everyone else who was secretly thinking that it was her birthday due to a mailing mistake the demon king made making everyone busy plotting a surprise party for her.