One of the major themes of “Super-Frog Saves Tokyo” is that there are some obligations a person must assume in life, even if recognition or reward is unlikely. Katagiri has spent his whole life taking on these kinds of duties. When his parents died, Katagiri dedicated himself to raising his brother and sister, putting them through college and arranging their marriages. At work, Katagiri takes on the hardest jobs, dealing with violent clients in a dangerous part of the city without ever receiving the praise he deserves. Frog changes Katagiri’s life because he helps him to understand that virtue is its own reward. He knows that Katagiri is already strongly motivated by a sense of duty and obligation. When Katagiri expresses reluctance to fight Worm, Frog appeals to this sensibility by telling him that this battle is “a matter of responsibility and honor,” not glory. If they succeed, no one will know, and if they are killed, no one will feel bad about the way they died. Yet Frog manages to make this sacrifice seem worthwhile, even desirable. He references Hemingway and Tolstoy, great authors who lend a heroic gloss to their characters’ decisions to go to battle without the promise of acknowledgment or gratitude.
At the same time, however, Frog does reward Katagiri for his service. At the end of the story, Katagiri has the satisfaction of having participated in a truly glorious, monumental battle, after having spent his life occupied with more mundane labors. But perhaps more importantly, Frog offers Katagiri recognition, honoring the daily struggles of his previous life and providing him with an emotional release he had never experienced. At the end of the story, it seems clear that Super-Frog saved not only Tokyo but Katagiri as well.
The first line of “Super-Frog Saves Tokyo”—“Katagiri found a giant frog waiting for him in his apartment”—recalls the famous opening to Franz Kafka’s story “The Metamorphosis,” which begins with the main character discovering that he’d transformed into an insect overnight. Like Kafka, Murakami tells the story of an ordinary man confronted with a shocking, unprecedented event that upends his life completely. In “Super-Frog,” the arrival of the amphibian stranger turns the normal order of things topsy-turvy so that frogs can be six feet tall, speak, and make tea. Earthquakes, previously assumed to be the product of plate tectonics, are revealed to be the work of a giant, angry worm. Katagiri experiences a sudden and shocking upheaval as well when, after years of working in the criminal districts of Tokyo, he is shot on the street near his office. The ground beneath the characters feet is literally unstable, as evidenced by both the Kobe earthquake and potential Tokyo quake.
The instability depicted in “Super-Frog” parallels the situation found in mid-1990s Japan. The Kobe earthquake, gas attack on the Tokyo subway, and collapse of the Japanese economy all weighed heavily on Murakami as he wrote the stories collected in after the quake. “Super-Frog” offers consolation to a traumatized Japan by showing how radical upheaval can sometimes lead to higher wisdom or satisfaction. Frog claims that an earthquake in Tokyo would make people appreciate the fragility of their city and, by his unspoken extension, the fragility of their existence. Katagiri gains an understanding of his own vulnerability, but he also emerges from the experience rejuvenated and with a deep sense of satisfaction.
The space beneath the earth’s surface is fraught with peril and anxiety as the home of the enemy and source of the potentially devastating earthquake. To reach Worm’s lair, Frog and Katagiri must pass through a series of places that are hidden from public view, just like the figurative “underground” in which Katagiri spent so much of his earlier life. Katagiri deals primarily with the shady criminal underworld in the red-light district of Kabuki-cho, which is filled with gangsters and “money flowing beneath the surface from one murky den to another.” This image of dirty, subterranean rivers makes the figurative concept of an underground economy a literal one. The thugs and gangsters of Kabuki-cho and fraudulent executives of Big Bear Trading all traffic in concealed corruption. Murakami thus uses the underground motif to draw parallels between the sleeping, monstrous Worm and criminal underworld, both of which are portrayed as lurking threats to Japanese society. The notion of the underground also connects “Super-Frog Saves Tokyo” to the Aum Shinrikyo subway attack and real-life Kobe earthquake. Both of these incidents, which had shaken the collective Japanese identity, were subterranean terrors.
Murakami has described Worm as a symbol of inner evil, which is a broad and flexible definition. Worm may represent the wickedness hidden inside the city of Tokyo (the criminal corruption that Katagiri battles every day) or the malice hidden inside the hearts of individual people. He may also represent the internal terrors of the imagination, a notion that Frog discusses often throughout the story. Because Worm apparently cannot be killed and his violent outbursts occur cyclically, Murakami seems to be arguing that human beings’ inner evil is similarly persistent and difficult to defeat. Frog complicates this reading when he says that he doesn’t consider Worm to be “the embodiment of evil.” Worm is not evil himself; rather, he is like a vessel that collects hatred from other sources.