Solopreneur case studies — 10/10
Solopreneur and side-business cases
217–239 of 239
Sanzzo: ¥100 million cumulative from a side-hustle blog — stacking over ¥20 million in six months on top of ¥3.77M/month, across multiple sites
Sanzzo (Tomomasa Yoshioka) started side-hustle blogging in June 2013 and passed ¥100M cumulative revenue by February 2020. His May 2019 monthly income was ¥3.77M across 7 sites — the structure behind sustaining ¥3–4M/month.
A BASE shop hit ¥420,000 in monthly sales, ranked 1,919th nationally. Six years from ¥10,000 to ¥538,000 average monthly, and a self-audit of a coupon's "borrowed demand"
A solo BASE shop owner grew average monthly sales from ¥10,000 to ¥538,000 over six years, then self-audited whether a coupon campaign borrowed future demand.
From optician to $28,000/month across three SaaS products: choosing only the battles you can win
Samuel Rondot, a former optician, hit $30,000/month with his first business — run entirely by hand, without writing code — and used it to go independent. He now runs three SaaS products in parallel, mostly through SEO, totaling $28,000/month. When LinkedIn's restrictions cut into one product, the others carried the business.
Acquired a blog with 400,000 annual pageviews in 6 days. Cut 550 articles down to 100, and visitors rose to 120% in 2 months
A company employee acquired a blog and YouTube channel with 400,000 annual pageviews as a side business. It closed in 6 days from buy offer to deal. After taking over, he trimmed 550 articles down to 100 and rewrote them, splitting the site into 3 categories. Two months after handover, visitor numbers had risen to 120%.
Full numbers from 3 rural minpaku properties: a leased + inn-license property paid back in 17 months on 3.45 million yen upfront — double the yield of a Housing Business Act property
Tetsujiro, who runs 3 unmanned minpaku properties in rural Japan, publishes upfront investment, annual sales, and cost breakdowns via spreadsheet. Property C — leased, operated under an inn business license — cost 3.4575 million yen upfront and generated 2.482 million yen in annual profit, paying back in 17 months, versus 35 months for Property A under the minpaku registration law — a twofold gap.
The Generalist: 60,000 Subscribers, $308K in Annual Revenue — a Paid Media Outlet Built on 40 Hours of Writing a Week
The Generalist, a newsletter dissecting tech companies in long-form, reached 60,000 subscribers and $308K (about ¥46.2 million) in annual revenue one year after going full-time. This piece examines the breakdown of a labor-intensive model built on 40+ hours of writing a week.
Walica: From 50 Users a Day to 300,000 a Month, on Two Hours Every Weekend for 4.5 Years
A bill-splitting calculator, "Walica," built by two second-year colleagues out of college, saw fewer than 50 daily users for its first full year after launch. Growth began once it started ranking in search. By March 2023 it hit 300,000 monthly users, having started with an annual operating cost of about 1,000 yen for a domain.
301 followers, ¥100,000/month in LINE stickers — how "releasing 10 titles" reversed a ¥120,000-a-year slump
Sticker creator Yukie Matsumoto hit ¥100,000/month in January 2023, seven years after her first release in March 2016, with only 301 Twitter followers and 404 on Instagram. The turning point was releasing 10 titles in 2022 after a 2021 with zero releases and only about ¥120,000 in annual income.
Quit Betting on One App, Went From $200 to $10,000/Month: A Side-Hustle iOS Developer Who Shipped 28 Apps in 8 Months
Max, a full-time iOS engineer, abandoned his strategy of building one perfect app and instead shipped 28 apps in 8 months. Revenue went from $200/month to $10,000/month (about ¥1.5M). The top 4 apps each earn about $1,500, and tool costs run $285–295/month.
20 years of a travel blog, from $8,000/month to $35/month. Reading the record of the fall, in numbers
Ikura, who runs the travel blog "Single Traveler" launched in 2004, discloses her revenue. At its peak she earned about 1.2 million yen a month (1 million from affiliates, 200,000 from AdSense); during the pandemic it fell to zero; as of November 2023 she earns about 5,000 yen a month on roughly 50,000 monthly PV.
The Kavalier: He Gave Up a $120,000 Salary for $6,000/Month — Doubling Subscribers Every Six Months
The men's fashion YouTube channel "The Kavalier" launched in 2015 with just 800 subscribers by year-end. Posting went from twice a month to every weekday, accumulating 500+ videos over 3 years, and in September 2018 he quit a $120,000/year job to go full-time. By the time of the interview: 57,000 subscribers, $6,000–7,000/month.
First revenue: 22 yen. One year and three months rebuilding 5 apps to reach 10,000 yen a month
A musical-instrument-store review site launched in October 2019 fizzled. Moving to Flutter, the developer released 5 apps, but ad revenue stalled at 22 yen on the first day. Right after implementing in-app purchases at the end of 2020, revenue reached 10,000 yen a month.
He left a company after 40 years to take over a 21-seat soba shop: an ¥8 million renovation, and half the customers were regulars from the old shop within 2 months of opening
Basho-an, a soba shop that ran for 20+ years in Narita, was taken over by former food-company executive Akifumi Takahashi via Batonz. He invested about ¥8 million in renovation, including ¥6 million for the kitchen, and opened the 21-seat "Nagomina." Within 2 months of opening, about half the customers were regulars from the previous shop.
¥100,765 in six months of side-hustle Notion templates. What happened when sales fell from ¥20,000 to ¥9,000 after losing the "featured" slot
A side-hustle FP started selling Notion templates in February 2025. Revenue averaged ¥20,298/month while featured, then halved to ¥9,000 after being dropped from the marketplace spotlight in June — ¥100,765 total over six months.
Zigpoll: Solo at $125,000/Month — the Day It Realized It Had Misread Who Its Real Customer Was
Jason Zigelbaum runs Zigpoll, a survey SaaS for e-commerce sites, solo — no co-founder, no funding — and reached $125,000 MRR (roughly ¥18.75M) in June 2026. The turning point was realizing he had been locking his best customer segment out of the tier where the features they needed lived.
From unemployed to owner of 3 businesses. A record of ~20 buy offers at an 80% reply rate, stacking up million-yen-class deals
Mr. Yoshida, in his 30s, left his job during the pandemic, sent about 20 buy offers on TRANBI with an 80% reply rate, and successively acquired a rental space in Kagurazaka, an esthetic salon in Chiba, and a call center in the Philippines for 3.7 million yen. On the third deal, sales halved right after closing.
eBiz Facts: $4,199/Month Reviewing Get-Rich-Quick Courses — Why It Pushes Readers Away From the Products It Reviews
Ireland-born Niall Doherty launched course-review site "eBiz Facts" in December 2018. It now averages $4,199/month over the trailing six months, with $2,708 in profit. The turning point was the very first project: buying a course with his own money and testing it for six weeks before writing anything.
Anniversary app "365-Day Anniversary" hit 10,000 yen a month, two months after launching a subscription
The anniversary-management app "365-Day Anniversary" reached 10,000 yen in monthly revenue two months after its subscription feature launched. The turning point was a design decision that didn't remove ads but instead made them always visible — and repurposed those same ads as the reason to buy the paid plan.
¥250,000/month on his 6th solo project — from a 50-yen-per-transaction failure to 50 paying users at ¥4,000/month
A developer who built six solo projects reached about ¥250,000/month in recurring revenue with his fifth product, an Instagram chatbot tool. His first product failed at a 50-yen-per-transaction commission and a few thousand yen a month; rethinking price point and billing model was the turning point.
Buttondown: A Stripe Engineer's Weekend SaaS — 5% a Month for Five Years to $75,000/Month
Justin Duke, a Stripe engineer, started newsletter SaaS Buttondown as a December 2016 side project. Roughly 5% monthly growth for the past five years brought it to $75,000/month (about ¥11.25M). He didn't go full-time until year seven.
A salaried employee's side-hustle secondhand-clothing shop hits ~¥3M in year one, profitable every month on 5-10 hours a week
Wakabayashi, a full-time employee, runs an online secondhand clothing shop across BASE, Mercari, and Yahoo Auctions. 2024 full-year sales were nearly ¥3M, with a strong month at ¥362K and a weak one at ¥127K, run solo from home in 5-10 hours a week.
The Formula Mom: Zero Ad Spend, 175K Followers, Six-Figure Annual Revenue — Joining a Formula Company in Two Years
Mallory Whitmore, a former teacher, started posting about formula-feeding in August 2020 and reached 175K Instagram followers and 30K email subscribers with zero ad spend. Annual revenue reached the low six figures, 80% from digital products and one-on-one consults, before she was acqui-hired by formula company Bobbie in roughly two years.
9,345 AI-generated images uploaded to Adobe Stock: the full record of reaching 878 downloads and $589/month (~¥95,000) over 9 months
A freelancer restarted AI-generated stock photo sales in June 2025 and, over 9 months, reached 9,345 cumulative uploads, 878 monthly downloads, and $589.59/month (~¥95,000). The turning point came in month five: an experiment where he resubmitted rejected images unchanged, tweaking only the tags and title — and about 50% got approved.