Hana Sugurono is a central character in the Spring Team and a seventeen-year-old girl who awakens in a post-apocalyptic world. She is the daughter of Takashi Sugurono, a key figure behind the 7SEEDS project, a fact that initially remains unknown to her and later becomes a source of significant conflict. Before the catastrophe, she had a distant but respectful relationship with her parents and spent much of her childhood on camping and mountain climbing expeditions with her father, which were, in truth, a form of covert training for survival in the future.

Hana projects an image of being strong, courageous, and highly self-reliant, often taking charge in difficult situations due to her exceptional survival skills and strong sense of justice. This exterior, however, masks a more vulnerable interior. She struggles with low self-esteem, finds it difficult to depend on others, and has a deep-seated fear of being a burden to those around her. Her upbringing, which honed her practical abilities, also left her somewhat isolated, and she admits to having had very few friends, with her boyfriend Arashi Aota being a notable exception. This combination of fierce independence and internal doubt makes her a complex figure who can be both charismatic and abrasive, sometimes clashing with others who share her stubborn nature.

Her primary driving force throughout the story is the desire to be reunited with Arashi, her boyfriend from the Summer B team, from whom she was separated when they were placed into different groups. This motivation is so profound that upon realizing she might never see him again, she briefly contemplates suicide. She regains her will to live after finding his name carved on a rock, which serves as proof he survived. Beyond her personal quest for Arashi, her role evolves as she uses her skills to help her companions from the Spring Team and others she meets, gradually finding purpose in contributing to the group's collective survival.

Her journey is marked by significant trauma and growth. She is forced to navigate the lingering hatred directed at her father, particularly from members of the Summer A team, who were subjected to brutal training by the project's leaders. This leads to persecution, including a near-death experience when she is deliberately caused to fall into an underground river. She survives this ordeal and, after a period of solitary wandering, loses some memories but eventually recovers. This isolating experience, however, helps her shed her guilt over her father's actions and fully awaken her innate adventurer's spirit. She ultimately transforms from a girl focused on personal reunion into a resilient survivor determined to carve out a new life in this changed world, culminating in her long-awaited reunion with Arashi.

Hana's most notable abilities are her physical prowess and extensive wilderness knowledge. She is a skilled free climber capable of scaling overhanging cliffs without ropes and is a strong swimmer, having been on her school's swim team. Her survival skills, taught by her father from a young age, include navigating terrain, finding food and water, and treating injuries. She also displays a natural affinity with wild animals, which tend to become attached to her despite her efforts to push them away. Her keen observational skills and quick thinking often allow her to assess dangerous situations before others, such as when she was the first to realize a guide was being controlled by a parasite.