Janu, a kind-hearted high school student known for his helpfulness, is fighting for his mother’s life, doing whatever it takes to afford her treatment. After school, he bravely chases down a thief, but his true battle lies at home—his mother, Sari, suffers from kidney failure. One day, as Janu and his friend Aji finish their classroom duties, they notice an AS card slipping from their teacher's pile of documents, revealing a place where all the bad kids are united, and who knows what that place is really about.

Janu picks up the Ace of Spades card that had fallen from the stack of documents. Aji approaches a confused Janu, and together they flip the card, revealing a message: "Open Fight" with an address underneath: "Benteng Utara." Curious, Aji urges Janu to visit the place. Though hesitant at first, Janu eventually agrees, pushed by Aji and his own curiosity. When they arrive, they discover the location to be an illegal fight arena for high school students. Pressured by circumstances, Janu is drawn into the fight, ultimately defeating the strongest fighter there.

In the crowd, Jack is intrigued by Janu’s victory and throws a Jack of Spades card, challenging him to a "Double or Nothing" fight. Pressured by the crowd, Janu accepts and defeats Jack. As they leave, a robber steals their bag of money, leading to a chase. After a fight on a bemo, the robber escapes, but drops a wallet with a Queen of Spades card, revealing the address to Queen’s headquarters. Exhausted, Janu and Aji head home.

The next day, Janu and Aji skip school to confront Queen at her headquarters. Aji sends Janu in first to face Queen, who is praying with incense. When Janu demands his money, she refuses, and they engage in a fierce battle. Despite her blindness, Queen proves to be an agile Wushu expert, but Janu ultimately defeats her. She reveals that the money has been moved to someone called King and hands Janu a King of Hearts card with King’s address on the back.

Janu and Aji enter King’s headquarters, where they find the guards distracted. Janu confronts King, but after a fierce battle, he struggles against him. Aji returns just in time to help, and together they capture King. Afterward, King reveals the location of the money. As they leave, Aji discovers a red Joker card tucked in his pocket.