Take Me to Koshien: ¥12.9M in 11 months, and the ¥100 ticket that multiplied IAP revenue by ten
Yu Furuta, a solo developer in Nagoya, shipped a high school baseball manager sim in November 2017. By the end of September 2018 it had earned ¥12.9M in total, peaking at ¥2.57M in August. With 48,000 downloads and about 3,000 DAU, 76% of revenue came from in-app purchases. The turn came from a ¥100 draft ticket.
A solo-built high school baseball game earned ¥12.9 million in eleven months? Was it just that the subject was Koshien?
The turning point the developer named was somewhere less obvious.
- A timeline of the third title, made with "¥1 million a month within a year, or retire" as the condition
- The roughly ¥100 draft ticket that multiplied purchase revenue tenfold
- A revenue curve that spikes only in August, and acquisition tuned to the calendar
- Rewarded video and 50 gems per bug report, two tweaks to the resource design
- The prior title's ¥3M, and the failures before it
Take Me to Koshien is a phone game where you coach a high school baseball team toward the national tournament.
It earned ¥12.9 million between its November 2017 release and the end of September 2018, eleven months in total.
The best single month was August 2018 at ¥2.57 million.
The author is Yu Furuta of furuApplications, a solo developer based in Nagoya. This was the third baseball title in his series.
The numbers invite a simple reading: the subject matter sold the game.
Yet when App Marketing Institute asked him what changed the purchase revenue, he didn’t point to any item that hands players a stronger athlete.
He pointed to a ¥100 ticket that lets you keep the third-year students who graduate and vanish when summer ends.
The third title, with retirement on the line
| Date | Event | Figures |
|---|---|---|
| March 2016 | Previous title, Let’s Build a Sandlot Baseball Team: Legend, ships | ~40,000 downloads and ~¥3M in total by September 2017 |
| Around June 2017 | Development starts, moving to animated 3D models | About six months of build time |
| November 2017 | Take Me to Koshien launches | Monthly revenue before launch was around ¥300,000 |
| August 2018 | Koshien season | ¥2.57M, the best month |
| End of September 2018 | Interview date | ¥12.9M cumulative, 48,000 downloads, ~3,000 DAU |
Furuta was already earning ¥300,000 a month from the previous title.
But with a wife and child, he felt that number would eventually stop being enough. So he gave the third game a condition: if it didn’t reach ¥1 million a month within a year, he’d quit app development.
His own blog says the earlier title left no financial slack and that this one had to beat it.
The revenue split is 76% purchases and 24% advertising. Of the 48,000 downloads, 40% were iOS and 60% Android.
Revenue per download came to about ¥260, the paying share was 5 to 6%, and each payer contributed roughly ¥3,000.
So one player in twenty pays ¥3,000, while the other nineteen watch ads or pay nothing at all.
On his blog Furuta writes that playing for free until the day you uninstall is completely fine by him.
What sold was the deadline attached to the player
Furuta credits the draft ticket for the jump in purchase revenue.
Because the game is set in high school baseball, third-year students retire after the summer tournament and leave your roster for good.
The ticket, priced around ¥100, guarantees that a graduating player can be registered to your alumni team.
After it shipped, purchase revenue rose tenfold and monthly sales went from the hundreds of thousands of yen to over ¥1 million.
In his words, “psychologically, the motive to avoid losing something may be stronger than the motive to acquire it.”
Here’s how we read that number.
The ticket sold because the game borrows its clock from the subject, more than because the audience loves baseball.
High school baseball caps a career at three years by rule. Players disappear no matter what the user does.
The developer didn’t design the deadline. The material arrived with one.
Furuta advises other developers to take a classic game such as baseball, shogi or othello and add original elements to it.
Frankly, what worked here was less the classic format than the fact that this particular classic replaces its cast every single year.
The scouting ticket, which improves the quality of incoming first-years, obeys the same calendar. It only means anything in the enrollment window.
A revenue curve that spikes in August
Dividing ¥12.9 million by eleven months gives an average near ¥1.17 million. That makes the ¥2.57 million peak 2.2 times the average.
The previous title showed the same shape, rising during summer vacation and the tournament season to a peak of ¥400,000.
The calendar sets the shape of revenue before any tactic does.
Acquisition was tuned to the same calendar.
- Putting the word Koshien into the subtitle lifted the app into search results it had never appeared in
- Keeping a record of which keyword settings paid off, and improving from there
- Showing review prompts only after a player wins a match for the first time, which collected 2,500 reviews on Google Play
The App Store listing shows the game still live as of September 2026, free with in-app purchases.
It’s rated 4.6 across 35,000 ratings, and the description says there’s no operations team because one person builds it.
One video of stamina, and 50 gems for a bug report
The advertising side was fitted to the same resource design.
He added an option to restore stamina by watching a video after a win. Rewarded-video revenue per download doubled.
Stamina is a finite resource that training consumes, and it doesn’t compete head-on with the paid items.
Furuta has written that banner ads pay a few tens of yen per click at a click rate near 1%.
Building 24% of revenue at that price means giving people a reason to watch.
For retention, he watched player behavior and found that the overwhelming majority closed the app right after losing a match.
So he began granting a training-efficiency bonus after defeats.
It’s a plain fix: put the next reason where people stop.
Early in development the app carried a line saying you might get a thank-you for reporting bugs. Reporters received about 50 gems, worth roughly ¥50.
Reports arrived with reproduction steps and screenshots, to the point that he wondered whether the sender was a professional tester.
Fifty yen hired an outside QA team.
The prior title made ¥3M, and before that he was burning savings
This ¥12.9 million sits on top of a count of failures.
The earlier title, Let’s Build a Sandlot Baseball Team: Legend, launched in March 2016. By September 2017 it had earned about ¥3 million, split ¥1.5 million in purchases and ¥1.4 million in ads, with a peak month of ¥400,000 and server costs of ¥1,000 a month.
Counting from the first sandlot game, the third attempt was the one that cleared ¥1 million a month.
- The first year or two after going independent ate his savings, and several early apps failed
- Before this project he abandoned a tennis game at 50% completion
- An escape game released in 2017 reached tens of thousands of downloads without giving anyone a reason to keep playing after the ending
His description of that period: starting something new feels like throwing a pebble into a large lake, where nothing happens.
The labor he charged himself for six months of development, any ad spend, the iOS and Android revenue split, and the trajectory after October 2018 aren't public. The ¥12.9 million is gross revenue before store fees, not take-home pay. The figures also come from an interview, reported by App Marketing Institute from his own account, with no third-party verification.
The ¥2.57 million peak came with August, once a year
Among solo-built phone apps, this game’s ¥2.57 million sits at the top end.
It’s also a number that arrives one month a year, with the monthly average closer to ¥1.17 million.
The draft ticket could sell the motive of not losing a player only because the subject itself supplied the deadline of players leaving after three years.
Put the same ticket in a game with no deadline and there’s no reason to buy it.
The limits deserve their own line.
These numbers belong to someone who set himself a one-year ultimatum and built a third title on the users and systems of a second one.
He also had local advantage, having found an art student at a Nagoya university festival to handle the previous game’s design.
And 2018 was still a period when individual apps grew on ads and store search.
As that record shows, the same playbook doesn’t pay the same way every year.
If this one impressed you
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Sources
- Reported アプリマーケティング研究所による古田悠氏(furuApplications)への取材記事(2018年10月12日公開)。2018年9月末時点の累計収益1,290万円、最高月商257万円、4.8万DL、DAU約3,000、課金率5〜6%、課金76%対広告24%、ドラフト指名チケットで課金収益10倍、動画視聴による体力回復でリワード広告収益2倍
- Reported 同メディアによる前作『草野球チームを作ろう!レジェンド』の取材記事(2017年9月5日公開)。約4万DL・累計収益約300万円(課金150万円/広告140万円)、ピーク月商40万円、サーバー費月1,000円、独立直後に貯金を取り崩した経緯
- Founder 本人ブログ「ふるあぷの真顔で読むブログ」の新作告知記事。2017年6月頃に制作開始し約6ヶ月で公開したこと、前作から約1年半空いたこと、3Dモデル表現への移行、前作の売上では余裕がなかったという記述
- Founder 本人ブログ(2018年2月6日)。収益の半分以上を課金ユーザーが支えていること、バナー広告は1クリック数十円でクリック率1%程度という認識、無課金のまま遊んでよいという方針
- Founder App Storeの掲載情報(2026年9月時点)。無料+アプリ内課金、評価3.5万件で平均4.6、デベロッパはfuruapp Inc.、説明文の「運営はいません」「1人で開発しているので」という記述