That reads to me like an embellished, Western take on the common "fox wife" stories ubiquitous in Japanese folklore. The prototypical version of this theme appears in the 8th century
nihon ryōiki (日本霊異記), i.e. Chronicles of Supernatural Tales of Japan.
In this tale, the protagonist went out searching for a wife, and found a beautiful girl looking for a husband. They thus married and produced a son. One day after the harvest, the wife brought refreshments to the women milling the rice. A dog chased after her, barking, and frightened her so much she leapt up to the roof revealing her true form as a fox. The husband, however, still loves the fox wife and begs her to come back and sleep with him.
In later stories, the awkward pickup lines were often replaced by the protagonist (always male) saving a fox and then finding a beautiful woman magically appearing on his doorsteps. The tax evasion can be, though isn't necessarily, one of the ways the fox repays his kindness.
For example, in Aichi regional folklore, a beautiful woman appears out of nowhere to marry a farmer, giving birth to a child. When their baby fell ill, however, the couple neglected their farm to nurse him back to health. Worried that there's no time left to sow the fields, the husband went out one day to discover the field has been planted - but upside down. He runs home to find his wife's tail dangling visibly, forcing the couple to separate, although the magistrate - not seeing the inverted harvest - exempts the farmer from taxes.
(Source: Aichi-ken Densetsu Shu, Collection of Aichi Prefercture Legends)
In other versions of the story, it is the son who noticed his mother's tail. That's the case in Izumi folklore, where the son grew up to become famed Abe no Seimei. Here, the fox came to the father out of gratitude for him saving her from a river, and later bestowed the power to understand beasts on her son.
(Source: Izumi Mukashi Banashi Shu, Collection of Izumi Folktales)
Note that the fox in these stories are merely foxes, not the Inari kami herself. However, in some, including the Izumi tale mentioned above, the fox wife is named as Kuzu-no-ha, a Messenger of the Inari God. Although there's a tendency even within Japan to confuse Inari with foxes, the two are not the interchangeable.
All in all, the story cited in that WordPress blog certainly has obvious and striking similarities to common Japanese folklore. However, the individual details do not quite match up with any version that I know of.