What the business is
Sekai is an iOS and Android app where people play with others' mini apps and make their own by describing an idea in a prompt.
The bet
That AI-generated mini apps will become a breakout consumer format, like short video, because people create and remix instead of scrolling.
Starting capital
$6M seed led by Mayfield in 2025, then a $20M Series A.
How it started
Founded in 2024, Sekai (Japanese for world) was the fourth startup of Lucky Zhang, who previously sold Yi+ AI to Apple in 2017 and Blacktail to ByteDance in 2020, and founded the Vietnamese streaming service NCT. It began with anime fan-fiction experiences and widened to general app creation after AI coding models improved sharply in 2025.
What happened
In 2025 Mayfield led a $6M seed. By June 2026 the company said users had created more than 15 million mini apps, over 200,000 a day, and spent more than an hour a day in the app. Khosla Ventures and Connect Ventures co-led the $20M Series A, with a16z Speedrun, Mayfield and others joining.
What has to be true
AI coding models improved enough in 2025 for non-programmers to build apps by prompt.
Shareable creations like interactive birthday cards gave the app a viral loop.
Zhang wanted a creative alternative to passive social-media scrolling.
Investors reacted to company-reported engagement of over an hour a day.
What can be applied
Time spent per user can be the investable signal when a product's pitch is participation, not content consumption, but here it is self-reported.
Aftermath
As of 2026-06-01 Sekai had closed its $20M Series A, was hiring in engineering and product, and planned creator monetization and celebrity partnerships; usage figures were company-reported.
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