Physical × Cyber

Keep mission-critical
systems running.

Watch both physical and cyber anomalies on one screen.
Five services that visualize, assess, monitor, remediate, and rebuild — without taking your systems offline.

01

You are holding a core system with no specification and no one left who built it — too risky to touch.

02

The system can't go down, so assessment and remediation keep getting pushed back.

03

Physical security and cyber monitoring run separately, and no one is watching the seam between them.

In an era where AI finds unknown vulnerabilities,
lacking security insight becomes a critical business risk.

Attackers use AI too. Vulnerabilities that were hard to find by hand are now exploited automatically and at low cost.

If the people building AI systems have no security perspective, those systems can't be defended. An engineer who understands both needs to be involved from the design stage.

Security
Penetration testing for financial institutions (GIAC GWAPT)
Started as a white-hat hacker at Nomura Research Institute. Consistently handled assessments meeting strict financial-sector standards such as PCI DSS and FSA guidelines.
Development
10+ years from requirements to production
Implementation experience spanning security, AI, and data platforms. The founder handles every phase directly — no external subcontracting.
AI
From machine learning through generative AI implementation
Supervised learning, causal inference, and reinforcement learning through RAG, AI agents, and MCP design. Evolved into generative AI while carrying the full ML context.

Five services that keep mission-critical systems running.

From visualizing specifications to assessment, integrated monitoring, remediation, and rebuild. Where to start depends on your current situation — we propose after listening.

Reo Onozawa

Former Nomura Research Institute / Founder, Green Tea LLC

Started as a white-hat hacker at Nomura Research Institute. After hands-on machine learning work, now supports the design and development of secure AI applications and the safe adoption of AI in the field.

Because the founder understands both security and AI, systems can be designed and implemented from an attacker's perspective. Every phase from requirements to production is handled directly.

GIAC GWAPT Registered Scrum Master
Full profile →
01
Security Engineer

Started as a white-hat hacker at Nomura Research Institute. Handled penetration testing and vulnerability assessment for financial institutions, consistently delivering assessment and remediation support based on OWASP, PCI DSS, and FSA guidelines. GIAC GWAPT certified.

02
Machine Learning Engineer

Applied supervised learning (demand forecasting, credit scoring, attrition prediction), unsupervised learning, time-series analysis, causal inference, and reinforcement learning in practice. Evolved into generative AI (RAG, AI agents, MCP) while keeping the full ML context.

03
Forward Deployed Engineer

Embeds into the client's organization, managing projects while handling development end to end. Supports assessment, design, implementation, and adoption.

The founder handles
every phase directly.

With a development vendor, members of varying skill levels join the project, so service quality is inconsistent. When the proposal team differs from the implementation team, what was agreed up front doesn't always make it into the build.

The founder handles every phase directly. No external subcontracting. From proposal to implementation, the person in charge never changes.

Development firm
  • Security, AI, and development split across a team
  • Handoffs occur between teams
  • Proposal owner differs from implementation owner
  • Staff change after the deal — or work is subcontracted out
Green Tea
  • Security × AI × development in one person
  • The founder handles every phase directly
  • Context never breaks from requirements to production
SERVICE 03 — Integrated Monitoring

Watch both physical and cyber anomalies
on one screen.

Omamori is an integrated monitoring service that uses your existing cameras and networks as-is, tying physical intrusion and cyber anomalies onto a single timeline. It is the core of the five-service system, available today.

▶ From detecting a combined attack to directing the response (about 1 min)
Learn about Omamori →

Reach out anytime.

It's fine if you're not sure where to start. The founder responds directly by the next business day.

Get in touch