Long, long ago, when the yen was the strongest currency in the world, there was a city called "Yen Town" by the immigrants. The Japanese residents resented the name and discriminated against the immigrants, calling them "Yen Thieves". This is the story about the "Yen Theives" who believed yen would help their dreams come true and came to the capital to realize their dreams. It is a rhapsody of anarchy, seen through the eyes of Ageha(=Swallowtail), a young girl living in Yen Town.
First "UNDO", then "PICNIC", now a new film from Shunji Iwai goes international! "SWALLOWTAIL."
The story opens with a young GIRL, the daughter of a prostitute, being taken in after her mother's death by GLICO, a prostitute from Shanghai. Glico came to Japan several years ago, hoping to become a singer. Instead, she ended up becoming a prostitute in "Yentown," a slum outside of Tokyo housing poor immigrants and Japanese social outcasts.
Glico has a tatto of an "Ageha" (swallowtail butterfly) on her chest. She names the young girl entrusted to her care "Ageha." Ageha starts working at "Aozora," a junkyard on the outskirts of Yentown. In the evenings, a motley crew of Yentown denizens gathers at Aozora to drink cheap liquor and listen to Glico sing. FEIHONG, a fellow Shanghai immigrant, watches her with love in his eyes.
One night, Ageha is attached by SUDO, a gangster from Katsushika Syndicate. ARROW, a former prizeflighter living in Yentown, saves Ageha but he accidentally kills Sudo in the process. As Arrow, Ageha, and her friends from the Aozora are burying the body, they discover a CASSETTE TAPE lodged inside Sudo's stomach. Playing the mysterious tape on the car stereo, they discover it contains the song "My Way."
Unbeknownst to our heroes, "My Way" tape contains a hidden stripe of magnetic date which can used to create counterfeit 10,000 yen notes. Rival gangsters KATSUSHIKA and RYOU RYANKI will stop at nothing to find the missing tape, which was last seen in Sudo's possession. Ryo and his henchmen massacre Katsushika's gang, then go to the Yentown brothel district in search of Sudo.
Back to Aozora, the Yentown denizens decode the tape and discover the hidden data. Within the next few days, they print out thousands of counterfeit notes, and become instant millionaires. With his new-found welth, Feihong buys an old warehouse and converts into a live music venue called "Yentown Club," with Glico and her back-up group installed as the house band. The club is a smashing success, and Glico becomes a huge star overnight.
Soon thereafter, record company executive HOSHINO, intent upon separating Glico from her low-class Yentown friends, informs the immigration authorities that FeiHong is an illegal alien. After his release from prison, Feihong does what he thinks is best for Glico - he accepts money from the record company in exchange for promising never to see her again. When the Yentown Band gets wind of the arrangement, they are furious. The group breaks up in a whirlwind of recrimination and anger.
Wanting to become a true "Yentown" girl, Ageha gets a butterfly tatto on her chest, just like Glico's. Then in order to re-establish the Yentown Club and bring all her friends back together, Ageha regains possession of the "My Way" tape and begins cranking out counterfeit bills again.
Meanwhile, REIKO, a former prostitute friend of Glico's, reveals Glico's sordid past to a tabloid REPORTER. Trying to save Glico's reputation, Feihong is arrested in connection with the counterfeiting case, and dies in police custody after a brutal interrogation. As the Yentown denizens face off against Ryou Ryanki's gangsters for their final battle, the story races to its fiery conclusion.