The archive · Consumer Apps · Product decision · 2023–2026
Ohayo Kai! Hero: Joy Nice Games' yokai idle RPG tops Japan's free charts in week one
Joy Nice Games (Legend of Mushroom) launched Ohayo Kai! Hero in Apr 2026; the yokai idle RPG hit #1 on both Japan app stores' free charts within days.
Joy Nice Games (Joy Net Games)
What the business is
Japan-market idle-raising RPG in which an office drone is promoted to night-shift commander of midnight yokai; maker Joy Nice Games built Legend of Mushroom (30M+ downloads) and other Japan idle hits.
How it started
Joy Nice Games (shown as Joy Net Games on Japanese stores) is the studio behind Legend of Mushroom (キノコ伝説, 30M+ downloads) and related idle titles. Its newest Japan title, Ohayo Kai! Hero (オハヨーカイ！ヒーロー) — a 'midnight yokai' idle RPG where a nameless corporate worker rises to night-watch commander — opened pre-registration in March 2026 and launched in Japan in April 2026.
What happened
Within days the game was #1 on Japan's iOS free-game chart (gamerch, April 12) and #1 on Google Play's free ranking (gamebiz, April 14). Game-i estimates put iOS revenue near ¥242M in April at an average grossing rank of #123 — a fast start driven by the free-draw pre-registration bonus and the studio's existing player base.
How it ended up
Still live as of 2026-09-02, but the launch spike cooled: Game-i estimates iOS monthly revenue fell from ¥242M in April to ¥168M in May, ¥119M in June, ¥110M in July and ¥76M in August, with the average grossing rank sliding from #123 toward the #350-430 range.
Background
Joy Nice Games (listed as Joy Net Games on Japanese stores) is the Chinese studio behind Legend of Mushroom (キノコ伝説, over 30M downloads) and a string of Japan-market idle RPGs. Its latest title, Ohayo Kai! Hero (オハヨーカイ！ヒーロー), launched in Japan in April 2026 with an unusually local premise: an office drone is promoted to night-watch commander of midnight yokai in a modern city.
The launch was engineered like a campaign: a tiered pre-registration program promised up to 444 free gacha pulls plus a limited skin, and the studio's existing idle-RPG audience was told to expect the same auto-battle, hero-formation loop wrapped in an occult-comedy setting. Within days the game hit #1 on Japan's iOS free-game chart (April 12) and #1 on Google Play's free ranking (April 14).
Monetization followed the familiar idle-RPG curve but cooled fast: Game-i estimates iOS revenue of about ¥242M in April at an average grossing rank of #123, dropping to ¥168M in May and roughly ¥76-119M per month through the summer, with the grossing rank sliding toward #350-430 by August 2026. The game is still live, with user rating ★4.39 from 1,975 reviews as of September 2026.
What has to be true
- Localized absurdity: the 'office drone on the yokai night shift' joke is tuned to Japanese salaryman culture and stands out in an idle-RPG market full of isekai fantasy.
- Proven loop reuse: the studio shipped the same auto-battle and hero-formation package that already produced Legend of Mushroom and Hello Dog Hero, cutting design risk.
- Free-draw pre-registration: promising up to 444 gacha pulls built a day-one install base that was powerful enough to take both stores' free charts within a week.
- Audience transfer: Legend of Mushroom's Japanese players followed the studio to the new title, giving the launch a starting base no new IP could buy.
What can be applied
A bizarre local theme plus free-draw pre-registration can top a country's charts within days — but chart-topping installs don't hold grossing rank unless the loop keeps players past the novelty.
Aftermath
As of 2026-09-02, Ohayo Kai! Hero remains live with steady content updates (Game-i lists new stages, events and equipment patches through mid-2026), but its Japanese grossing position has decayed from the launch peak: average iOS rank #123 in April 2026 to roughly #350-430 by August, with estimated monthly iOS revenue falling from ¥242M to ¥76M. Android revenue and post-launch downloads are undisclosed; the pattern matches a pre-registration-driven spike that monetized a dedicated idle-RPG audience without converting it into a long-term top-grossing title.
Sources
- 【Google Play(4/14)】★5キャラ「リンネア」が新登場の『原神』が首位キープ Joy Nice Gamesの新作『オハヨーカイ！ヒーロー』が無料ランキング首位に
- iPhone 無料ゲームアプリランキング【2026年4月12日付】
- 「オハヨーカイ！ヒーロー」事前登録で最大444連ガチャ！社畜が夜番人に成り上がる放置RPGを徹底解説
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