¥50,000–70,000 a Month in Royalties From 24 Kindle Books: 16 Months of Real Data on "Volume-Production" Self-Publishing, ¥750,000 Cumulative

Most Kindle publishing income reports cherry-pick the “hit months.” The value of this case is the opposite: it discloses royalties for all 16 months from the start, without skipping a single one. Twenty-four books for ¥50,000–70,000 a month, nothing flashy, but it contains every “per-unit number” you need when planning self-publishing as a business. The author even discloses a prior failure in audio streaming before turning to Kindle.

The Complete Monthly Royalty Record

• Books published: 24 (in about a year and a half from March 2021)
• Setup: enrolled in KDP Select, 70% royalty rate
• Revenue sources: sales + Kindle Unlimited pages read (about ¥0.5 per page)
• The most recent title (15,000 characters, ¥480) earned about ¥6,000 in its first month

The shape of the curve speaks volumes. The first three months hovered at ¥5,000–14,000/month. A level the author might call “hopeless if you convert it to an hourly wage.” Month four (June) jumped to ¥36,000, and by month six it entered the ¥50,000s. For the following 13 months it never once fell below ¥50,000. Once the number of titles crosses a threshold, it turns into low-variance stock income.

Breaking Down the Unit Economics

Each book is 10,000–20,000 characters, the equivalent of 5–10 blog posts, sold at around ¥480 and earning ¥2,000–3,000 per month. One book’s worth of writing labor converts into a permanent stream of a few thousand yen per month, and the integral over 24 books becomes ¥50,000–70,000/month. The author also mentions once “writing a book he was fired up about in a single day”. The practical reality of volume production lies on the side of “a thin book every month,” not “a thick book once a year.”

At the 70% royalty setting, each ¥480 sale returns about ¥336 to the author. The average of ¥2,000–3,000 per book per month corresponds to roughly 6–9 copies sold, and on top of that sits the Kindle Unlimited pages-read revenue. Lining up 24 books that “each sell only a few copies a month” works precisely because of this two-layer revenue structure.

The floor is Kindle Unlimited. All-you-can-read pages pay out about ¥0.5 each, and one book the author cites was read roughly 20,000 pages for ¥11,041. Beyond buyers paying ¥480, readers who “don’t buy but do read” also generate revenue. The fit between a few-hundred-yen practical book and the subscription catalog is a precondition of this volume model.

The Road to Kindle — Failure in Audio Streaming

Before Kindle, the author spent three months posting daily on Stand.FM (audio streaming) and ended at around ¥2,000/month. He goes as far as writing that he “nearly gave up on internet business, doubting his own sense and talent.” That the same person reached ¥50,000/month merely by switching mediums shows the difference in outcomes stems not from talent but from the structure of the medium, flow-type (broadcasts stream past and vanish) versus stock-type (books stay on the shelf). Three months of daily audio accumulated nothing. Sixteen months and 24 Kindle books accumulated.

The numbers make it even clearer. Even on Kindle, the first three months totaled ¥29,000 in royalties, an “unrewarded period” not much different from the Stand.FM days (¥2,000/month). The difference came after. Audio streaming restarts from zero every month no matter how long you continue, but on Kindle, the books you wrote stay on the shelf next month. The jump to ¥36,000 in month four came not from increased effort but from three months of accumulated inventory starting to sell simultaneously. When the author writes “even an ordinary person with no publishing experience can earn this much. That’s the dream,” the basis is not talent but this accumulation structure. ¥2,000 a month from a medium that vanishes, ¥50,000 a month from a medium that stays. The same person produced both numbers.

The Mechanism of Accumulation

Kindle publishing is a game of “building a shelf,” not “hitting it big with one book.” Even if each book’s average revenue is tiny, volume creates reader circulation (readers pick up the author’s other books), and backlist sells frontlist. The figure of 24 books for ¥60,000/month (¥2,500 per book) is an extremely practical planning unit for anyone starting out. In our editorial judgment, 13 months without dropping below ¥50,000 is the product of design rather than luck. A structure of ¥480 books at a 70% royalty, stacked 24 deep, smooths out each title’s hits and misses on its own.

The main battleground for discovery is Amazon search and Kindle Unlimited recommendations, but the author also promotes via Twitter and a LINE official account, and says promotion is necessary. Still, it remains the same “marketplace type” as app-store-driven app distribution, one of the few arenas open to people without their own media presence.

The Structure of the Plateau

The constraints are low price points and platform dependence. The plateau at ¥50,000–70,000/month is a function of the price band (a few hundred yen) and the ceiling on the reader base. Not leaving the ¥50,000–80,000 range for 13 months means the ceiling of a 24-book shelf sits around there. That KDP’s terms and rates hold the lifeline is the same structural risk as the low multiples in YouTube channel sales. Adding more titles yields diminishing returns on the backlist, and the KU per-page rate (about ¥0.5) is a variable Amazon sets unilaterally.

Paths through the ceiling are visible in other cases. The education app that grew to ¥4.61 million/year did so by choosing a market with large search demand. The ceilings of paid note articles and online salons are set by unit price and the size of the devoted fan base. Structurally, maintaining the ¥60,000/month Kindle shelf as a “completed asset” and building a different shelf fits better than endlessly pushing royalties alone.

Afterwards — the Income That Grew Outside Royalties

The author of the source blog now claims over ¥5 million/month in income “related to” Kindle publishing. But this is not individual royalties. It includes Kindle consulting and content sales. “Selling how to earn from publishing” pays more than “earning from publishing”, a staple structure of the info-content genre, and this ¥5 million should not be read as a reproducible endpoint of the royalty model. The reproducible unit remains “24 books for ¥50,000–70,000/month.”

Conditions and Limits of Reproduction

• The usable core: business planning on the unit economics of ¥2,000–3,000 per book per month. The setup of KDP Select at 70% with the KU floor. The decision to switch to a stock-type medium after burning out on flow-type media (SNS, audio streaming)
• Harder to import: skill at “choosing genres that sell” is a precondition that doesn’t show up in the numbers, and not all 24 books necessarily hit at the same rate. The start was in 2021 — there is no guarantee the same curve can be drawn in today’s more crowded KU recommendations. And since ¥50,000–70,000/month is the ceiling, a plan that positions this as primary income does not hold

Related Cases

• Dokozono’s ¥50,000/month app — the app version of the same “stack small” pattern
• The education app at ¥4.61 million/year — the upside of stock revenue