Brain Rental / Rental Brain

Rent a brain.
A new kind of consulting.

Not as heavy as hiring a consultant. Not as lonely as figuring it out alone.
Brain Rental gives you access to an experienced professional's thinking —
exactly when you need it, for exactly as long as you need it.

Get in touch See pricing
What is Brain Rental

What you get

Brain Rental (also known as Rental Brain) is on-demand access to an experienced professional's thinking. Not a retainer. Not a long-term contract. Just the brainpower you need, when you need it.

Instead of delivering thick reports, I help you think through your challenge and walk away with a clear next step. Think of it as a professional sparring partner — someone who listens, organizes, and helps you move forward.

No industry limits

Business, technology, strategy, creative — I work across domains. If I can't help, I'll tell you honestly.

One session is fine

No obligation to continue. Use it once, or make it a regular thing. Your call.

Dialogue, not reports

We talk. I listen, organize your thoughts, and help you identify concrete next actions.

Strictly confidential

Everything discussed stays between us. No exceptions.

6 elements

The 6 forces behind Brain Rental

Not just consulting. Not just AI. Six forces combined to tackle your challenge.

🧠

Experience

25+ years

International business, management, CTO, government projects. Hard-won wisdom from the real world.

⚡

AI

Artificial Intelligence

Cutting-edge AI for research, analysis, and creation. Human judgment multiplied by machine speed.

📚

Knowledge

Cross-domain

Business, technology, planning, storytelling, mathematics. A deep library across disciplines.

🌐

Network

Global connections

Trading company, government, private sector. An international network built across 6 countries.

🔍

Search

Real-time intelligence

Live information gathering and verification. Proposals grounded in the latest data.

✦

Intuition

The sixth sense

Judgment that doesn't show up in data. Pattern recognition sharpened by decades in the field.

Who it's for

People who use Brain Rental

Have a business idea but can't organize it
Running a company with no one to talk to
Want to enter Japan but don't know where to start
Need a sparring partner for a pitch or proposal
Want an outside perspective on your strategy
Balancing work with caring for aging parents
How it works

A typical session

01

You talk

Tell me what you're working on, what's stuck, what you need.

02

I organize

I extract the core issues and structure them clearly.

03

We explore

I offer directions, options, and concrete suggestions.

04

You decide

You leave with a clear next action. The decision is always yours.

Pricing

How pricing works

First session
Free (15 min)
After that: You decide the price
After each session, you decide what the consultation was worth to you.
Pay what you believe is fair. That's how Brain Rental works.
About

Who you're renting

Toshikazu Shiroiwa
Toshikazu Shiroiwa
AUTHOR & ADVISOR ON AGING JAPAN

USC mathematics graduate. Eight years at a Japanese trading company managing government ODA projects across Oceania, Africa, and Central Asia, then IT executive and CTO. Author of Still Moving, a memoir of seven years caring for both parents at home. Today I combine 25+ years of experience with AI to advise individuals, businesses, and government. About the book

Not sure if this is for you?
That's exactly what the free session is for.
Let's talk.

Contact now

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