cosa

Real expertise.
Always available.

We're building aikoo — an AI character platform that turns real human knowledge
and experience into personalized conversations, available to anyone, anytime.

Try aikoo
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Why we're building this

Everyone has knowledge and experience worth sharing.

A teacher who's guided thousands of students.
A counselor who's helped people through tough times.
An expert who's spent decades mastering their craft.

But their reach has always been limited by time, language, and geography.

We spent over 10 years building one of Japan's largest skill-sharing marketplaces — connecting millions of people with experts across every field.

We saw firsthand how powerful it is when the right knowledge reaches the right person at the right moment.

Now, AI is making it possible to break those limitations entirely.

We're building the platform that lets real human expertise flow to everyone who needs it — through AI characters that carry the knowledge, personality, and warmth of real people.

aikoo

AI Character Platform

aikoo turns real human expertise into AI characters you can talk to. From lifestyle advice and professional consulting to entertainment — each character is built on genuine knowledge and experience, delivering personalized conversations that actually help.

  • AI characters across lifestyle, wellness, consulting & more
  • Built on real human knowledge — not generic AI
  • Natural, personalized conversations
Visit aikoo.me

Who we are

Ryu Ishihara

Ryu Ishihara

Co-Founder & CEO

Joined coconala — Japan's largest skill marketplace with over 5 million users — as employee #1, leading both marketing and product management from launch through IPO. Founded COSA in San Francisco in 2025.

Hiroaki Shuto

Hiroaki Shuto

Co-Founder & CTO

Joined coconala as its earliest engineer, building the technical foundation that scaled to millions of users. Led multiple new product launches and core platform architecture. Co-founded COSA with Ryu.

Company Information

CompanyCOSA, Inc.
Founded2025
Headquarters178 Bluxome St., San Francisco, CA 94107, USA
CEORyu Ishihara
Japan Office COSA LLC
1-10-8 Dogenzaka, Shibuya-ku, Tokyo, Japan
Legal CounselTMI Silicon Valley LLP
Contactinfo@co-sa.co

Get in touch

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