The Edo-era couriers ran from Nihonbashi in Tokyo to the Sanjō Bridge in Kyoto — five hundred and fourteen kilometers. The fastest, three days and three nights. An ordinary traveler took fourteen to fifteen days.
Fifty-four post stations lined the way. Shinagawa, Kawasaki, Kanagawa, Hodogaya, Totsuka, Fujisawa, Hiratsuka, Ōiso, Odawara… Each station carried its own scenery, its own story. The journey progressed in units called “stations.”
HIKYAKU’s conversion of daily scores into a 514-kilometer journey is not decoration. “Distance” as a metaphor has a deep effect on habit formation — and there is solid cognitive science behind it.
Why distance works for habits
In behavioral psychology, there is a phenomenon called the goal-gradient effect.
As one approaches a goal, the frequency and intensity of effort increases. Clark Hull observed this in animal experiments in 1934, and modern human-behavior research has repeatedly confirmed it.
Concrete examples:
- Customers redeem coffee-card stamps roughly twice as quickly when “2 stamps from free” compared to “9 stamps from free” (Kivetz et al., 2006)
- Gym members visit more frequently as they approach their target weight
- Loan repayment rates accelerate as the remaining balance shrinks
In other words, the human brain is wired so that “motivation arises automatically when the distance to the goal is visible.”
And that “distance” is stronger as a concrete spatial metaphor than as an abstract number. “From Shinagawa to Kawasaki” activates the reward system more strongly than “45 more days.”
Two roles of dopamine
This is where dopamine comes in.
Dopamine is often introduced as a “pleasure chemical,” but more accurately, it is the “chemical of expectation and exploration.” It creates the motivation to take the next step toward a goal.
Research shows that dopamine:
- Peaks not when reward is received, but when reward is predicted
- Activates most strongly in “almost there” situations
- Is also released when seeing new places or scenery
The Tōkaidō stations design stimulates all three.
- The next station is visible → reward prediction
- Almost there → achievement anticipation
- New scenery at each station → novelty exploration
The number “45 days” alone is far weaker, for the brain, than the sensation of stations sliding past on a map.
What the Edo travelers may have understood
Interestingly, Edo-era travelers seem to have understood this psychology intuitively.
The stations along the Tōkaidō were spaced about 10 kilometers apart — half a day’s walk to reach the next station. “Almost there” sensations arrived multiple times a day, by design.
Hiroshige’s woodblock series “The Fifty-Three Stations of the Tōkaidō” depicted each station’s distinct scenery for a reason. Because each station offered a different view, travelers retained the motivation to walk on.
This was not merely travel infrastructure — it was, arguably, a psychological architecture for sustaining long-distance walking.
Modern metabolism is also a journey
For modern people, “continuing keto or fasting for several months” is hard. Most quit within three weeks of starting.
Through the lens of the goal-gradient effect: “three months ahead” is too distant for the gradient to ignite. The brain conserves dopamine for “very distant goals.”
The Tōkaidō metaphor works because it decomposes “a very distant goal” into a sequence of short goals called “the next station.”
- Eat today’s planned snacks → forward N kilometers
- Continue 30 days → past Shinagawa
- Continue 60 days → reach Odawara
- Continue 90 days → cross the Hakone pass
When the goal shifts from “be healthier” to “next station,” the brain receives each small daily forward step as a daily small reward.
Another meaning of “knowing where you are”
When HIKYAKU shows your Tōkaidō position, what’s visible is “where today’s self stands.”
This is not metaphor. The running total of the last 30 days’ scores converts in real time to a position on the road. Yesterday’s choices determine today’s place on the map.
This connects to “self-efficacy,” the concept introduced by Albert Bandura — the felt sense that “my own action produces results” is itself the strongest motivator for continuation.
Each glance at the map confirms “I carried myself here.” The visualization of “a few kilometers to the next station” pulls tomorrow’s choices forward.
Living at the station, not at the goal
Setting “complete the Tōkaidō” as a goal is, in fact, not the important part.
The true value of the Fifty-Three Stations lies not in the destination (Kyoto) but in the fifty-four stations carved along the way. Each station holds its own achievement and its own memory.
Instead of “I lost X calories in 90 days,” the journey is remembered as “I passed Shinagawa, rested at Totsuka, looked up at the Hakone pass.”
Life may not be a race with a destination. The view from the station where you currently stand — that accumulation may, in fact, be the journey itself.
To live cleanly and beautifully is, perhaps, to fully see today’s station’s view before moving on.
This article is for informational purposes and is not medical advice. Please consult a physician for any health concerns.