Arisa Maresato, also known as Alice, is a young girl who becomes a member of the main survivor group. She is seven years old and in the second grade of elementary school. Physically, she has pink hair and purple eyes, with a noticeable mole or tear mark near one eye. Her journey begins in tragedy; while trying to find shelter with her father, a newspaper reporter, they were refused entry by a household. In the ensuing confrontation, her father was killed, leaving her alone and vulnerable to the approaching zombies. She is rescued by Takashi Komuro and Kohta Hirano, who risk their own safety to save her, and she subsequently joins their group, accompanied by a small dog named Zeke who was also present during the rescue.

In terms of personality, Arisa is characterized by her innocent, bright, and generally positive attitude, which is notable given the horrific circumstances of the outbreak and the loss of her parents. The older members of the group often remark on how well she copes with the trauma she has endured. While she can display surprising strength and maturity at times, her fundamental nature is that of a lively child, and she serves as a reminder to the hardened survivors of their own humanity. She looks up to the other members of the group as older brothers and sisters, forming a new surrogate family. This loyalty makes her stubbornly refuse to be left behind for her own safety, as she is unwilling to lose another family.

Arisa's role in the story is primarily that of a mascot or a protected charge rather than a combatant. The group goes to great lengths to shield her from the worst of the violence and to prevent her from having to fight. Her presence provides a critical emotional anchor for the other survivors, giving them a concrete reason to maintain their moral code and hope for the future amidst the collapse of civilization. She develops particularly strong bonds with several members. She is often seen with Kohta Hirano, acting almost as a little sister to him; she teaches him songs, helps him by fetching ammunition, and her presence softens his more aggressive tendencies. She is also close with Saya Takagi, who calls her Munchkin and acts in a strict but caring, sisterly or maternal manner toward her. Her relationships with Takashi and the others are similarly familial, built on the foundation of their heroic rescue.

Despite her lack of fighting ability, Arisa is not entirely helpless and possesses notable abilities that contribute to the group. Her most remarkable skill is her proficiency with bicycles; she can ride with great speed and perform impressive stunts, such as bunny hopping onto displays, allowing her to navigate quickly and evade danger. She also proves resourceful, using a packet of firecrackers given to her by a police officer to create distractions and redirect the zombies when necessary. Her greatest strength, however, is her emotional resilience. While she does cry and show her fear, she remains optimistic and brave, refusing to let her grief consume her. Over the course of the story, she grows from a terrified, grieving child into a more courageous and integral member of the group, actively looking for ways to help and inspiring her older companions to persevere.