Beatrix Amerhauser, often called by her nickname Bea, is a main character introduced in the anime and manga series. She is a former college student from Germany who traveled to Japan with a singular, passionate goal: to eat the best sushi of her life. Her journey is not merely a vacation but a dream she worked hard to achieve, having saved money from part-time jobs to experience authentic Japanese culture firsthand.

Beatrix is a free-spirited and bubbly young woman whose enthusiasm for Japanese culture is boundless. She becomes visibly excited when discussing any topic related to Japan, from its history and foods to its traditional customs. Her personality is marked by a kind and friendly nature, but she is also remarkably goal-driven and persistent. This determination is best exemplified by her willingness to fight through hordes of zombies to deliver fresh fish to a sushi chef, refusing to let a global pandemic derail her dream. She possesses an unshakable and practical outlook, showing no embarrassment about mixed bathing in a hot spring, which she justifies by referencing historical Japanese customs where men and women bathed together for medicinal purposes. This行为 reflects her straightforward and non-judgmental approach to life, starkly contrasting with some of her companions.

Beatrix first encounters the main group of survivors when they come across her truck, which has run out of gas and is surrounded by zombies. The group intends to help, but Beatrix emerges from the vehicle donned in samurai armor and single-handedly dispatches the undead, impressing Akira, Kenichiro, and Shizuka with her combat skills. She then pleads for their assistance in delivering her precious cargo of frozen fish to the last surviving sushi chef in Takasaki. Akira, seeing that all-you-can-eat sushi is on his bucket list, eagerly agrees, and the group successfully clears a path to the chef, where Beatrix finally gets to savor her long-awaited meal, moved to tears of joy by the experience. After this event, she continues traveling with the group, becoming a core member of their party.

Within the group, Beatrix forms distinct bonds with each member. She is a close friend to the protagonist, Akira Tendou, with whom she shares a similarly energetic and optimistic personality. Their dynamic is one of easy camaraderie and mutual understanding as they face the apocalypse together. Her relationship with Kenichirou Ryuuzaki, or Kencho, is more complex; while they are close friends and travel companions, she is often repulsed by his perverted and lecherous suggestions, such as when he proposes she work as a bikini bar waitress offering special services. She frequently allies with the more reserved Shizuka Mikazuki to shut down Kencho's inappropriate ideas, though the two women share a friendly and supportive relationship.

Beatrix serves as one of the group's primary fighters, alongside Akira. Her combat prowess is significant, and she is depicted as a woman in peak physical condition capable of wearing heavy samurai armor while easily dispatching large groups of zombies. Her armor is functional, offering her protection such as fire and bite resistance. Beatrix is a weapons expert, demonstrating proficiency with a variety of traditional Japanese arms. She is remarkably talented with a katana, wielding dual blades as part of her samurai gear, and is skilled with a naginata (a polearm), which she uses with enough strength to cut a zombie cleanly in half. She is also an expert archer, capable of landing precise headshots on zombies with a bow and arrow or a crossbow. Her fighting style is rapid and efficient, and she has proven capable of holding her own not only against the undead but also against other weapon-wielding human foes.