Tatsuko is a dragon girl residing with her grandfather, the powerful black dragon Wong, behind the Water Curtain Cave. While Wong possesses significant magical knowledge, Tatsuko initially displays no inherent magical abilities herself. When Wukong escapes capture by the Ao Kingdom's forces, Tatsuko aids him, guiding the fugitive to her grandfather's domain. After Wukong steals the Ruyi Cudgel and floods their home, Wong tasks Tatsuko with monitoring Wukong's actions.

Despite Wukong's frequent recklessness, Tatsuko demonstrates persistent loyalty. She witnesses his entrapment within Buddha's Five Finger Fist and informs the monkey tribe, initiating their search for a holy monk to free him. Following Tang Sanzang's liberation of Wukong, Tatsuko assists in rescuing Sanzang from demons and then joins the pilgrimage to India. She travels alongside Wukong, Sanzang, Hakkai, and Sa Gojo, primarily motivated by the prospect of adventure.

Tatsuko thrives in chaotic situations, characterized by a spirited and occasionally temperamental disposition. Her interactions with Wukong often involve bickering and threats of abandonment, maintaining a non-romantic dynamic reminiscent of children's quarrels. She exhibits independence, choosing to follow the group based on personal interest rather than obligation. Her role represents a significant narrative departure from the original *Journey to the West*; instead of transforming into a horse, she remains an active, unaltered dragon participant throughout the journey.

Tatsuko maintains her presence within the core group across the series' diverse and often surreal events, including an unexpected Western-themed conflict involving treasure maps and rival factions. Her survival is confirmed, distinguishing her from versions of the tale where analogous characters meet an early demise.