Top 10 Best Ethical Hacker / Penetration Tester in Tokyo (Verified & Reviewed Guide)

Introduction

Tokyo organizations face constant pressure from phishing, ransomware, cloud misconfigurations, and web application attacks—often while supporting hybrid work, third-party vendors, and fast-moving product releases. That’s why many companies (and some high-profile individuals) search for an Ethical Hacker / Penetration Tester in Tokyo: to find and fix exploitable weaknesses before attackers do.

In this guide, you’ll learn what penetration testing typically includes, what it costs in Tokyo, and how to choose a provider that matches your risk level, industry expectations, and reporting needs.

We set out to build a “Top 10” list, but only five providers could be included without guessing or inventing details. Every entry below is limited to what is publicly verifiable (or clearly marked as “Not publicly stated”).

About Ethical Hacker / Penetration Tester

An Ethical Hacker / Penetration Tester legally simulates real-world attacks against your systems—web apps, APIs, cloud environments, internal networks, mobile apps, and even employees (when social engineering is authorized). The goal is to identify vulnerabilities, prove impact, and deliver clear remediation guidance.

You typically need a penetration test when you are:

• Launching or redesigning a web application, API, or mobile app
• Migrating to cloud infrastructure (AWS/Azure/GCP) or changing network architecture
• Preparing for customer security reviews, audits, or enterprise procurement requirements
• Responding to a security incident or suspicious activity (follow-up validation)
• Building a security program and need a baseline risk assessment

Average cost in Tokyo (typical market ranges)

Pricing varies widely based on scope and depth. In Tokyo, penetration testing commonly falls into these broad ranges:

• Small web app / API test: often ¥300,000–¥1,500,000
• Larger applications, cloud, or multi-scope engagements: often ¥1,500,000–¥5,000,000+
• Red team / adversary simulation: often ¥3,000,000–¥10,000,000+

These are general market ranges. Exact pricing depends on the target environment and rules of engagement.

Licensing or certifications

Japan does not have one universal “penetration tester license” requirement that applies to all engagements. What matters most is written authorization (scope and permission) and demonstrable competence.

Commonly requested certifications (varies by client and industry) include:

• OSCP / OSCE (Offensive Security)
• CEH (EC-Council)
• CISSP (ISC2) for broader security leadership credibility
• GIAC certifications (SANS) such as GPEN / GXPN (varies)

Key takeaways

• Pen testing is a controlled, authorized attack simulation—not a vulnerability scan.
• Deliverables should include proof of impact, reproduction steps, and fix guidance.
• Expect cost to vary by scope, environment complexity, and reporting requirements.
• No single license is mandatory, but credentials + documented methodology + authorization matter.

How We Selected the Best Ethical Hacker / Penetration Tester in Tokyo

We evaluated providers using practical, buyer-focused criteria:

• Years of experience: Publicly stated tenure or demonstrable track record (where available)
• Verified customer review signals: Only publicly available review signals when clearly attributable (otherwise “Not publicly stated”)
• Service range: Web/app/API, cloud, internal network, red team, incident response support
• Pricing transparency: Any published pricing guidance, scoping clarity, and expectation-setting
• Local reputation: Visibility in Japan’s security market, enterprise adoption, and recognizable presence in Tokyo

This guide uses only information that is publicly available and confidently known. If a detail (like phone numbers, direct emails, or public review summaries) wasn’t reliably available, it’s marked as Not publicly stated rather than guessed.

About Tokyo

Tokyo is Japan’s largest business hub, with dense concentrations of finance, technology, media, retail, and multinational headquarters. That mix drives strong demand for penetration testing—especially for internet-facing services, mobile apps, and cloud-based platforms supporting large user bases.

Security testing demand is often highest in neighborhoods and business districts such as:

• Chiyoda (including Otemachi and Marunouchi)
• Minato (including Roppongi, Shiodome, and Shinagawa areas)
• Shibuya
• Shinjuku
• Chuo
• Koto (notably for tech and logistics zones)

Exact service coverage by neighborhood is Not publicly stated for many providers, but most Tokyo-based firms serve clients across the metro area and nationally.

Top 5 Best Ethical Hacker / Penetration Tester in Tokyo

#1 — GMO Cybersecurity by Ierae

• Rating: Not publicly stated
• Years of Experience: Not publicly stated
• Services Offered: Penetration testing / security diagnosis (service scope varies), web application assessment, mobile application assessment, cloud-related security support (Varies / depends)
• Price Range: Not publicly stated
• Contact Phone: Not publicly stated
• Contact Email (if available): Not publicly stated
• Website (if available): https://gmo-cybersecurity.com/
• Google Map or ProfessNow or Yelp Link (Leave it blank)
• Google Reviews Summary (summarized, not copied; if unknown write “Not publicly stated”): Not publicly stated
• Best For (Budget / Emergency / Premium / Family-Friendly / etc.): Premium, product companies needing structured security testing

#2 — Flatt Security

• Rating: Not publicly stated
• Years of Experience: Not publicly stated
• Services Offered: Application security assessments (web/API), penetration testing (scope varies), security consulting and guidance (Varies / depends)
• Price Range: Not publicly stated
• Contact Phone: Not publicly stated
• Contact Email (if available): Not publicly stated
• Website (if available): https://flatt.tech/
• Google Map or ProfessNow or Yelp Link (Leave it blank)
• Google Reviews Summary (summarized, not copied; if unknown write “Not publicly stated”): Not publicly stated
• Best For (Budget / Emergency / Premium / Family-Friendly / etc.): Startups and engineering teams wanting practical remediation support

#3 — LAC Co., Ltd. (ラック)

• Rating: Not publicly stated
• Years of Experience: Not publicly stated
• Services Offered: Security assessments/diagnostics (including penetration testing where scoped), incident response support (Varies / depends), managed security services (Varies / depends)
• Price Range: Not publicly stated
• Contact Phone: Not publicly stated
• Contact Email (if available): Not publicly stated
• Website (if available): https://www.lac.co.jp/
• Google Map or ProfessNow or Yelp Link (Leave it blank)
• Google Reviews Summary (summarized, not copied; if unknown write “Not publicly stated”): Not publicly stated
• Best For (Budget / Emergency / Premium / Family-Friendly / etc.): Enterprises seeking broad cybersecurity capabilities alongside testing

#4 — NTT Security (Japan)

• Rating: Not publicly stated
• Years of Experience: Not publicly stated
• Services Offered: Penetration testing (scope varies), red teaming/adversary simulation (Varies / depends), security consulting and managed security services (Varies / depends)
• Price Range: Not publicly stated
• Contact Phone: Not publicly stated
• Contact Email (if available): Not publicly stated
• Website (if available): https://www.nttsecurity.com/
• Google Map or ProfessNow or Yelp Link (Leave it blank)
• Google Reviews Summary (summarized, not copied; if unknown write “Not publicly stated”): Not publicly stated
• Best For (Budget / Emergency / Premium / Family-Friendly / etc.): Premium, global organizations needing standardized security programs

#5 — Deloitte Tohmatsu (Cybersecurity services)

• Rating: Not publicly stated
• Years of Experience: Not publicly stated
• Services Offered: Penetration testing and offensive security (Varies / depends), red team-style exercises (Varies / depends), cyber risk and governance support (Varies / depends)
• Price Range: Not publicly stated
• Contact Phone: Not publicly stated
• Contact Email (if available): Not publicly stated
• Website (if available): https://www2.deloitte.com/jp/en.html
• Google Map or ProfessNow or Yelp Link (Leave it blank)
• Google Reviews Summary (summarized, not copied; if unknown write “Not publicly stated”): Not publicly stated
• Best For (Budget / Emergency / Premium / Family-Friendly / etc.): Regulated industries needing executive-ready reporting and governance alignment

Comparison Table

Cost of Hiring a Ethical Hacker / Penetration Tester in Tokyo

In Tokyo, most penetration testing is priced per engagement rather than hourly, because scope definition, rules of engagement, and reporting requirements drive the real effort. For buyers, the most important step is a clear scope: what’s in, what’s out, and what “success” looks like.

Average price range (typical)

• Basic external assessment / small web app: often ¥300,000–¥1,500,000
• Multi-application or internal network testing: often ¥1,500,000–¥5,000,000+
• Red team / advanced simulation: often ¥3,000,000–¥10,000,000+

Emergency pricing (if applicable)

Penetration tests are usually scheduled. If you need rapid validation after an incident (or before a hard deadline), some providers may offer expedited timelines. Emergency pricing and 24/7 availability are not publicly stated for many firms and typically depend on capacity.

What affects cost

• Scope size: number of apps, APIs, IP ranges, cloud accounts, and user roles
• Depth of testing: authenticated vs unauthenticated, business logic testing, exploitation proof
• Environment complexity: microservices, multi-cloud, legacy systems, SSO/IAM, WAF/CDN layers
• Compliance/reporting needs: executive summaries, audit-ready evidence, retesting requirements
• Time constraints: compressed schedules and after-hours coordination (Varies / depends)
• Rules of engagement: social engineering, phishing simulations, physical testing (only if authorized)

Frequently Asked Questions (FAQ)

How much does a Ethical Hacker / Penetration Tester cost in Tokyo?

Typical penetration testing in Tokyo often starts around ¥300,000 for small scopes and can exceed ¥5,000,000+ for complex environments. Exact cost depends on scope, depth, and reporting requirements.

How to choose the best Ethical Hacker / Penetration Tester in Tokyo?

Choose based on scope fit, methodology, and reporting quality—not just brand. Ask for a sample report, tester certifications (if applicable), a clear rules-of-engagement document, and a retest option.

Are licenses required in Tokyo?

A universal penetration testing license requirement is Not publicly stated as a general rule in Japan. What is required is explicit written authorization and a defined scope to ensure the work is lawful and controlled.

Who offers 24/7 service in Tokyo?

24/7 availability for penetration testing is Not publicly stated for many providers and is often not standard. Some firms offer 24/7 managed security services, while pen tests are typically scheduled engagements.

What’s the difference between vulnerability scanning and penetration testing?

Vulnerability scanning is largely automated and focuses on finding known issues. Penetration testing includes validation, exploitation (where allowed), and human-led testing for logic flaws and chained attack paths.

Can a Tokyo penetration test be done in English?

Often yes, but it depends on the provider and assigned team. Confirm bilingual support upfront, including whether the final report and remediation workshop can be delivered in English.

What should be included in a penetration test report?

A good report usually includes scope, methodology, findings with severity ratings, evidence, reproduction steps, business impact, and prioritized fixes. Executive summaries are helpful for leadership stakeholders.

How long does penetration testing take?

A small web app test may take about 1–2 weeks including reporting, while larger or multi-scope engagements can take several weeks. Timelines vary based on scope and stakeholder availability.

Do I need to provide test accounts or access?

For authenticated testing, yes—test accounts, roles, and sometimes VPN access are needed. Providers should specify secure access methods and data-handling expectations before work begins.

Is retesting included after fixes?

Sometimes, but it depends on the engagement terms. Ask whether a retest window is included, how many findings can be revalidated, and what evidence is required to confirm remediation.

Final Recommendation

If you’re a startup or product team that needs actionable findings and close collaboration with engineers, start by scoping a focused web/API test and consider providers known for practical remediation workflows (for example, firms positioned around product security services).

If you’re an enterprise with multiple systems, third-party risk, and formal procurement, prioritize providers that can handle broader programs (multi-scope testing, standardized reporting, and cross-team coordination).

For regulated industries (finance, telecom, critical infrastructure, or large B2B SaaS), choose a provider that can deliver audit-aligned documentation, executive-ready reporting, and well-defined rules of engagement—even if the price is higher.

Get Your Business Listed

If you’re a Ethical Hacker / Penetration Tester in Tokyo and want your business details added or updated, email contact@professnow.com. You can also registe & Update yourself at https://professnow.com/