Colleen Adams, an ordinary middle school student, discovers an apparently injured yellow piglet that turns out to be hungry. After feeding it her apple, the piglet sneaks into her school bag and disrupts her classes. The creature later reveals itself as Prince Tonrariaano the Third from planet Buringo, capable of speech and flight. He gifts her a magical compact called the Dream Tonpact, which affixes a pig snout to her nose upon opening. Reciting "Ba Bi Bu Be Burin" transforms her into Super Pig—a pink piglet with flight and super strength—allowing her to aid endangered civilians.

Colleen resents this form, having aspired to resemble her idol Cutey Chao as a conventional magical girl. Tonrariaano explains that gathering 108 pearls through virtuous deeds might unlock an alternate heroic form, but misuse of powers depletes pearls via karma. A critical clause exists: exposure of her dual identity curses her to remain a pig forever. Juggling her civilian life with superhero duties strains her, especially as she harbors a crush on soccer team captain Koichi Mizuno, who idolizes Super Pig without recognizing Colleen. Her best friend Masami Yamakawa provides romantic encouragement.

Multiple figures endanger her secret: classmate Jimmy Matsumoto, an investigation-savvy science enthusiast probing Super Pig’s appearances; her father Shinichiro Kokubu, a newspaper editor relentlessly chasing a Super Pig scoop; and her oblivious younger brother. During a crisis, a fleeting magical girl form fails due to lacking powers, forcing her back into Super Pig. In the penultimate episode, classmates uncover her identity, triggering the irreversible transformation. Koichi initially rejects her but ultimately accepts Colleen. This revelation culminates her journey toward integrating both identities despite the permanent outcome.