What do real-life thoroughbreds, anime horse girls and Japanese idols have in common? For a brief moment, these elements came together to make for the hottest video game in the world — and they might kickstart a new trend in Japanese games overseas.

On June 26, Tokyo-based developer Cygames released the English port of Umamusume: Pretty Derby, a game that tasks players with training equine-human hybrids (all of them female, as suggested by the title combining the Japanese words for “horse” and “daughter” or “girl”). Players then have their horse girls — inspired by actual thoroughbreds across the history of Japan’s competitive horse racing scene — run simulated races around tracks and, upon victory, the girls break into idolesque concerts.

It’s exactly this quirky mix of anime aesthetics and casually addictive gameplay that you might expect to resonate deeply with a niche audience and no one else — but that’s where Umamusume bucked the trend. Two weeks after the release of the English-language port and largely thanks to a number of livestreamers who gave Umamusume a try, the game at one point amassed more than 87,000 concurrent players on the digital games marketplace Steam.