P-bi̍t, a slow-witted boy who is always bullied by classmates, is actually an android created by the country of B-lē to fight invading monsters. His dream, however, is to run a food stall in front of his school and serve sweet potatoes to students. This 10-year-old boy yearns for the company of friends, so when the mysterious one-eyed girl Ka-lm appears, it’s like a dream come true. But terrible things start to happen. Their classmate B-g disappears, and P-bi̍t and Ka-lm discover that the principal is actually an android who devours students with the worst grades in the class and makes them into canned food. Ka-lm tells P-bi̍t that if everyone gets dumber by eating the venom glands of monsters, then no one will become a victim. But when P-bi̍t’s classmates eat their venom-laced lunches, they pass out and don’t regain consciousness. P-bi̍t unexpectedly learns Ka-lm is a spy from the neighboring country Hēng-hok. Ka-lm made friends with P-bi̍t to seek revenge for her country, because B-lē has turned the people of Hēng-hok into monsters, including Ka-lm’s mother and older brother…