The story is set in the futuristic, hybrid city of San Fransokyo, blending elements of San Francisco and Tokyo. The protagonist, Hiro Hamada, is a 14-year-old robotics genius who engages in illegal underground bot fights to earn money. Despite his intelligence, Hiro is directionless, much to the concern of his older brother, Tadashi Hamada.

Tadashi, a dedicated student at the prestigious San Fransokyo Institute of Technology, introduces Hiro to the world of robotics research. Encouraged by Tadashi, Hiro showcases his groundbreaking invention—microbots, tiny robots that can connect and form various structures through a neural interface. Inspired and eager to join the institute, Hiro attends the school's showcase but suffers a devastating loss when a fire ignites, resulting in a tragic accident that claims Tadashi's life while he attempts to save Baymax, an inflatable healthcare companion designed to assist with medical needs. Overcome with grief and anger, Hiro seeks solace in Baymax, who is activated after Tadashi's death. As Hiro discovers that his microbots have been stolen by a masked villain named Yokai, he embarks on a mission to uncover the truth behind his brother's death and reclaim his invention. In his quest, Hiro assembles a makeshift team of Tadashi's friends to form the superhero group "Big Hero 6." Together, they face various challenges and learn how to work as a cohesive unit. The major conflict centers around Hiro’s internal struggle with grief and the external battle against Yokai revealed to be Alistair Krei, a businessman whose motivations are rooted in revenge and a desire for power. As tensions escalate, Hiro's quest for vengeance risks endangering himself and his friends, causing him to confront the darker aspects of his emotions. In the film’s climax, Hiro learns an invaluable lesson about heroism: it is not about revenge but about using his gifts to help others. This change in perspective leads to a dramatic confrontation with Yokai, where Team Big Hero 6 ultimately prevails through ingenuity and teamwork. Hiro honors his brother's legacy not by harboring anger but by using technology to create a better future.

Trust vs. Mistrust (Infancy): In this stage, which occurs from birth to about 18 months, infants learn to trust their caregivers to meet their basic needs, such as food and comfort. If caregivers are reliable and loving, the infant develops a sense of trust. If not, the infant may grow to feel insecure and fearful of the world.

Autonomy vs. Shame and Doubt (Early Childhood): From about 2 to 3 years old, children begin to assert their independence. They want to do things for themselves, like potty training and dressing. If they are encouraged and supported, they feel confident in their abilities. If they are overly controlled or criticized, they may develop feelings of shame and doubt about their skills.

Initiative vs. Guilt (Preschool Age): Spanning roughly ages 3 to 5, children start to initiate activities and take on new challenges. They explore their environment and come up with play ideas. If their initiatives are encouraged, they build confidence and a sense of purpose. However, if they are discouraged or made to feel guilty for their desires, they may struggle with initiative.

Industry vs. Inferiority (School Age): From around 6 to 12 years, children start school and begin to compare themselves to their peers. If they succeed in schoolwork and social skills, they feel industrious and capable. If they struggle or receive negative feedback, they may develop a sense of inferiority, feeling less competent than their peers.

Identity vs. Role Confusion (Adolescence): During the teenage years (approximately 12 to 18), individuals explore their personal identity and values. They ask questions about who they are and what they want to become. If they successfully navigate this exploration, they develop a solid sense of identity. However, if they become confused about their role and place in the world, they may experience uncertainty about themselves.

Intimacy vs. Isolation (Young Adulthood): In this stage, which occurs in the late teens to early 40s, the focus shifts to forming meaningful relationships. Individuals seek deep connections with others, whether through friendships or romantic partnerships. Successfully building these relationships leads to a sense of intimacy, while failure to connect can result in feelings of isolation.

Generativity vs. Stagnation (Middle Adulthood): From about 40 to 65 years, adults focus on contributing to society and helping the next generation. This can be through parenting, work, or community involvement. If they feel productive and involved, they experience generativity. However, if they feel stagnant or unproductive, they may struggle with a sense of dissatisfaction.

Integrity vs. Despair (Late Adulthood): In this final stage, which typically occurs after age 65, individuals reflect on their lives. If they look back with a sense of fulfillment and acceptance, they experience integrity. If they feel regret or disappointment about their choices, they may face despair, leading to feelings of hopelessness about their life’s meaning.

Trust vs. Mistrust (Infancy): Although Hiro is not an infant at the film's beginning, we can see traces of trust established through his supportive family environment, especially his older brother, Tadashi. Hiro's initial trust in his brother sets the stage for his later development.

Autonomy vs. Shame and Doubt (Early Childhood): Hiro displays autonomy through his innovative and self-driven nature. However, his experiences with failure and loss begin to instill doubt in his abilities, especially following the tragic event that leaves him without his brother.

Initiative vs. Guilt (Preschool Age): Early on, Hiro demonstrates initiative through his entrepreneurial spirit in creating mini-bots. However, following the incident involving his inventions and losing Tadashi, he experiences guilt, which plays a significant role in his character development.

Industry vs. Inferiority (School Age): Hiro's involvement in robotics and his acceptance into the college where Tadashi attended can be seen as a struggle with industry (competence in his skills) versus feelings of inferiority. After Tadashi's death, Hiro wrestles with self-doubt and feelings of inadequacy, pushing him towards a darker path initially.

Identity vs. Role Confusion (Adolescence): This stage is particularly significant for Hiro as he grapples with his identity without his brother. He struggles with understanding who he is without Tadashi and questions his place in the world, leading him to initially abandon his passion for robotics and his identity as an inventor.

Hiro Hamada's identity in Big Hero 6 is shaped by his journey through grief, innovation, and friendship, set against the multicultural backdrop of San Fransokyo. Erikson's theory is valid here, as it emphasizes Hiro's developmental challenges following his brother's death, including his initial isolation and eventual connection with friends. Each stage of Erikson's model reflects Hiro's struggles and growth, illustrating how overcoming these psychosocial conflicts is essential for his identity formation and psychological development.

In Big Hero 6, Hiro Hamada starts as a brilliant but troubled teenager and evolves into a mature individual by the film's conclusion. Erikson's theory aptly illustrates his development through various life stages, each marked by significant challenges and themes. Initially, Hiro grapples with identity and loss following the death of his brother, feeling isolated and unsure of his place in the world. As he matures, these concerns shift; Hiro begins to focus on building connections with his friends and using his talents for the greater good. His journey highlights the transition from the struggle for identity to the pursuit of intimacy his growth is ultimately marked by reconciliation with his past and a newfound sense of purpose in fostering community and friendship.