It's Okay to Not Be Okay - Characters & Cast

His primary motivation is to protect and care for his autistic brother, Sang-tae, a responsibility drilled into him since childhood. This evolves into a desire to protect his new-found family, including Ko Mun-yeong, and ultimately, to find his own identity and happiness separate from his role as a caretaker.

Initially, Gang-tae is a selfless caregiver who completely suppresses his own needs and desires for the sake of his brother, Sang-tae. He wears a metaphorical mask, hiding his exhaustion and longing for a normal life. His encounter with Ko Mun-yeong forces him to confront his deep-seated resentment and the trauma of feeling unloved by his own mother. Over the series, he learns to acknowledge his own pain and desires, transitioning from someone who exists only for others to an individual who can accept love and pursue his own happiness. His arc is about learning that it's okay to be 'selfish' and that he deserves to have a life of his own.

Initially, her motivation is a selfish desire to possess Gang-tae, whom she sees as a 'safety pin' to her 'bomb'. This possessiveness slowly transforms into a genuine desire for connection and family. Her ultimate motivation becomes breaking free from her mother's psychological torment and protecting the new family she has built with the Moon brothers.

Ko Mun-yeong begins as a classic antihero, presenting a cold, arrogant, and selfish exterior due to what is described as an antisocial personality disorder, stemming from a deeply abusive childhood. She is emotionally stunted and doesn't understand social conventions or empathy. Through her persistent, almost obsessive relationship with the Moon brothers, she gradually learns about warmth, connection, and vulnerability. Her journey is one of thawing her frozen emotions, learning to trust and love, and transforming from a 'monster' created by her mother into a human capable of genuine connection and empathy.

His initial motivation is safety and stability, which he relies on Gang-tae to provide. This broadens to include his desire to protect his younger brother, a role he eventually embraces fully. His ultimate motivation is to become his own person, an artist who is no longer defined solely by his trauma or his disability.

Sang-tae, who is on the autism spectrum, starts the series completely dependent on his younger brother, Gang-tae, and trapped by his trauma from witnessing their mother's murder. His world is rigid, governed by routine and his love for dinosaurs and Ko Mun-yeong's books. His arc is a powerful journey toward independence and self-actualization. He learns to confront his greatest fear (butterflies), distinguish his role as an older brother from a dependent, and pursue his own dream of becoming a professional illustrator. He evolves from being the person who needs protection to becoming a protector himself, ultimately declaring his independence from Gang-tae to find his own identity.