Mari Sakuragi runs Itadaki, her family's popular okonomiyaki restaurant in Takara shopping district, fiercely proud of her work and dedicated to perfecting her signature "Marispecial" recipe. The Itadaki faces mounting financial pressure from the new Takara Mall, built by the Yabusame corporation with shops deliberately mimicking the district's unique style, drawing business away from local establishments like hers.

She shares a deep, childhood bond with Shuta Aoi, Ran Akagi, and Koki Suido, the "RGB" trio named for their distinct hair colors. Mari also held a close connection to Koki's younger sister, Asumi Suido, who tragically died a year earlier in a school fire. Mari carries lingering guilt and unresolved grief over Asumi's death, blaming herself and Shuta for the outcome.

The community places heavy expectations on Mari to win the upcoming 24th Ward Gourmet Festival, viewing her success as crucial for revitalizing the struggling district; the winner gains a collaboration with a major convenience store. Feeling the pressure, Mari seeks advice from Shuta, Ran, and Koki, but finds them distracted by their own issues. Her festival involvement coincides with discoveries that its funding traces back to the Takara Mall through a Yabusame-linked paper company.

Mari becomes unintentionally caught in perilous events. In one critical incident, her puppy Daisy leads her onto active train tracks where she becomes trapped as a train approaches. This emergency spurs the RGB trio, who received a mysterious vision and phone call seemingly from Asumi, to intervene using newly acquired abilities. They rescue Mari and prevent disaster just in time. This event underscores how Mari, despite her preference to avoid extraordinary conflicts and concentrate on her restaurant, finds her life intertwined with the ward's larger struggles through her connections. Her journey reflects themes of community resilience, personal loss, and perseverance against external pressures.