Reiko and her younger brother Hiroshi live together with their parents who own a tofu shop, and business hasn't been good. One day, they find a mysterious cat-like alien who introduces herself as Ponko, a traveling salesman from a distant star system. Ponko claims to trade in various products, including 'Hahise', and offers a highly advanced copying machine that can copy anything, to solve Reiko's family's money woes. But with no money to pay for the machine, Ponko suggests Reiko to pay with 'Hahise'... but what is 'Hahise', really?
Things quickly go downhill for Reiko...
General tropes:
- Blue-and-Orange Morality: Space civilization as a whole regards Hahise simply as trade goods, and Ponko really doesn't understand the significance of a 'soul' for humans. She even suggests Reiko to ask her mother to produce more siblings for more Hahise.
- Deal with the Devil: Reiko realizes too late that paying with Hahise means Ponko will take her brother's soul. In a subversion, the deal is done out of Blue-and-Orange Morality rather than actual malice, and the final chapters of the manga are spent trying to undo it.
- Hugh Mann: Ponko's superior's attempt to disguise as human only gets the clothing right, and neglects its obviously alien appearance.
- No Place for Me There: Once Reiko makes a copy of herself and resets the situation to 5 years ago, the original Reiko leaves earth to join Ponko travelling the universe, at peace that her brother will still have his beloved sister before she falls into despair.
- Wizards from Outer Space: Ponko is a cutesy-looking alien saleswoman from space, but might also be described as a soul-eating succubus con artist with all the magical jargon replaced by sci-fi elements.
- Your Soul Is Mine!: What Hahise really is. By accepting to pay with Hahise, Ponko takes Hiroshi's Hahise as payment for the copy machine.
