High school student Kyosuke Shikijo is the most talented member of the school's martial arts of the fist club. His late father was detective and Kyosuke share his father's strong sense of justice. Kyosuke also has a secret. Kyosuke likes to wear female underwear and transforms himself into the alter ego "Hentai Kamen," wearing female underwear and gaining superhuman powers. This unusual interest also comes from his parents, with his father a masochist and his mother a sadist. By chance, Kyosuke gets the underwear of female high school student Aiko Himeno. With her underwear, he gains various pervert techniques and attempts to protect Aiko from a dirty and heinous teacher.

In 1969, Kenji, an elementary school kid and his friends built a secret base during their summer holidays. They fantasized that they had to fight villains who were out to conquer the world and wrote them in the Book of Prophecies. Years later in 1997, Kenji becomes a convenience store manager and leads a regular life after giving up his dreams to become a rock star. His boring life is suddenly turned upside down when his old classmate dies mysteriously and an entire family in the neighbourhood disappears. At the same time, a religious cult and its mysterious leader, Friend emerges and a strange chain of events duplicating exactly the events described in the Book of Prophecies follow. Is this the beginning of the end of the world? Who is Friend?

Riku, the heir to a corporate conglomerate, is determined to go through life never owing anything to anyone on principle. However, one day he nearly drowns in a river and is saved by a homeless girl named Nino. To repay his debt, he begins living together with her on the banks of the river as her lover.

The final showdown, and the final reveal. Who is Friend? How can he be stopped?

Naoko Yamada (Yukie Nakama), a female magician, and Jiro Ueda (Hiroshi Abe), a genius physicist, are back again to solve the mystery of supernatural happenings. In a village where people are cured, a battle royale is held to find the successor for shamen Kamahaeri. Naoko attempts to gain big money by participating in the battle royale, while Jiro is invited to the village to stop this custom. Naoko and Ueda then challenges this amazing trick ..

An appassionato art student and a dispassionate college girl make a vow, saying they would meet each other again in the Florence Cathedral after 10 years.

Plain, timid and obsessed with jellyfish, Tsukimi is a far cry from her idea of a princess. Her tepid life as a jobless illustrator comes complete with roommates who harbor diehard hobbies that solidify their status as hopeless social rejects. These wallflowers run a tight, nun-like ship, but their no-men-allowed-not-no-one-not-no-how bubble is unwittingly burst after Tsukimi brings home a rescued sea jelly and a beauty queen... who's actually a guy. When the threat of losing their cozy convent inspires this glamour boy to turn the neurotic entourage into a portrait of success, will Tsukimi take her chance to bloom, or will she end up a hot mess?

Set 15 years after "Twentieth Century Boys," Kanna (Airi Taira) reunites with several main characters from the first film in an attempt to stop Friend's increasing influence over the world and continued plans to eliminate humanity, as detailed in the New Book of Prophecy.

Ippei Akabane (Takaya Kamikawa) is an unpopular novelist. He barely makes ends meet writing serials novels under different pen names. Daigo Kurei (Shinji Takeda) is on death row. He killed four women twelve years ago. During his murdering spree, he sent pictures of his decapitated victims with flower decoration to the police. The murders and photos caused widespread panic in Japan. One day, Ippei is contacted by Daigo from prison. He asks Ippei if he wants to interview him and write his memoirs. Soon, more women are killed in the same grisly manner as the serial murders from twelve years ago. Now, Ippei becomes the prime suspect of the police and Ippei must quickly find the real murderer. Based on the novel "The Serialist" by David Gordon (published by Simon & Schuster; Original edition on March 9, 2010).

Mirai Suzuki (Yuko Oshima) becomes responsible for her mother's debt which is owed to loan shark Kaoru Ushijima (Takayuki Yamada). To begin paying off her mother's debt, Mirai begins working at a dating cafe. Meanwhile, Jun (Kento Hayashi) is the ambitious and greedy company president for an event group. To borrow money, Jun visits Kaukau Finance owned by Kaoru Ushijima.