About
Built by recruiters who ran Japan’s first AI-first search firm.
We built Headhunt.AI for ourselves. Then we bet our entire agency on it. Now, eight years and thousands of placements later, we’re opening it up.
From frustration to first principles
In 2017, Ken Charles and Cody Pettit started ExecutiveSearch.AI on a simple thesis: the recruiting industry wastes most of its labor on work that could be automated, and the result is worse for candidates, worse for hiring managers, and — eventually — worse for recruiters too. On February 1st, 2018, they launched Japan’s first AI-first search firm.
Headhunt.AI started as our internal tool
For years, Headhunt.AI was our competitive advantage, not a product. We integrated GPT-3 in Spring 2022, rebuilt the matching stack on large language models through 2023, and kept refining the platform against every placement, every rejection, and every follow-up from our own agency operation. Every feature in the current product earned its place through daily production use.
In 2023, Monstarlab Inc. acquired the company
In October 2023, Monstarlab Inc. (TSE: 5255) — a publicly-traded Japanese AI/DX consulting firm — acquired ExecutiveSearch.AI via a share purchase agreement. Monstarlab has delivered enterprise digital, AI, and product engineering projects for some of Japan’s largest organizations, with deep experience across recruiting technology and HR platforms. The backing gives Headhunt.AI enterprise-grade operational standards, legal infrastructure, and the balance sheet to invest in Japan’s recruiting future for the long term.
Today: two sister companies, one platform
ExecutiveSearch.AI K.K. is a pure technology company operating the Headhunt.AI platform. ESAI Agency K.K. is the licensed recruiting business (有料職業紹介事業許可) that runs on Headhunt.AI as its first customer. The two operate under separate data environments, separate privacy policies, and separate contracts. That separation is deliberate — it’s what lets us offer the platform to other recruiting agencies without conflict, and to enterprise customers with the data-isolation guarantees they need.
Regulatory standing
Headhunt.AI has filed notification with Japan’s Ministry of Health, Labour and Welfare (厚生労働省) as a 第4号特定募集情報等提供事業者 — the regulatory class introduced by the October 2022 amendment to the 職業安定法 (Employment Security Act) for AI-driven candidate aggregation platforms. Most AI sourcing services in Japan operate as 第3号 (registration-based platforms — BizReach, LAPRAS, Findy, Wantedly). 第4号 is specifically the legal category for platforms that collect candidate information from public professional sources without per-candidate registration — the operating model Headhunt.AI uses.
第4号 is the smallest of the four classes by an order of magnitude — only 6 services are registered under it nationally, out of 1,642 services across all four classes (per the most recent MHLW aggregate, status as of June 1, 2025, published March 2026). For Headhunt.AI, the registration is straightforward compliance with the framework that the 2022 amendment created specifically for this category of platform. We treat it as table stakes for operating responsibly in Japan, not as a marketing trophy. Full regulatory disclosure →
Founders
Meet the founders
Ken Charles
American entrepreneur and recruiter. Ken started in Wall Street recruiting and has run on-the-ground Japan recruiting since 2014. He led the technical and product direction of Headhunt.AI from day one, and was one of the first founders in Japan to integrate LLMs (GPT-3, spring 2022) into a live recruiting operation.
Cody Pettit
Co-founder of ExecutiveSearch.AI K.K. and Head of Data Operations. Cody runs the data team behind Headhunt.AI’s AI candidate scoring and production evaluation. He came into recruiting from an unconventional path and brings a candidate-first perspective to every process decision. Long-time partner to Ken — they’ve worked together in Tokyo since before the first version of the platform existed.
Principles
How we run this business
We use it before we sell it
Every feature ships after we’ve used it in our own agency. If our recruiters won’t touch it, we don’t ship it.
Honest numbers only
Every performance claim we make comes from ESAI Agency production data. We’d rather quote a smaller, defensible number than a flashy one that doesn’t hold up.
Data isolation is a feature, not a setting
Platform customers and our own agency operate under separate environments, separate contracts, and separate privacy policies. This isn’t a compliance checkbox — it’s how the business is structured.
Want to talk?
We answer our own inbox. Write us and a real person on the founding team will reply within one business day.