Coinbook

What Coinbook does

Coinbook, now operating as BACKSEAT Exchange Inc. (BACKSEAT暗号資産交換業株式会社), is a Japan-registered cryptocurrency exchange operator founded on May 18, 2018 and headquartered in Tokyo. The platform serves both retail and corporate/institutional clients with a unified product set covering a sales-counter (販売所) for simple buy/sell, an exchange venue for spot trading in ADA/JPY and NIDT/JPY pairs, an OTC desk for large-volume transactions in BTC/ETH/ADA/NIDT against JPY (JPY 5M–300M per ticket), staking services, IEO token offerings, and third-party custody. All customer crypto assets are held 100% in segregated cold wallets under a distributed multi-signature security architecture, and customer JPY balances are held in client-classified trust with SBI Clearing Trust. The company is registered with the Kanto Local Finance Bureau (No. 00026) and is a member of JVCEA, JADA, JCBA, JPCrypto-ISAC, and the Japan Security Council.

The business earns revenue primarily through maker/taker trading fees on the exchange, bid-ask spreads on sales-counter and OTC transactions, fixed JPY withdrawal fees (JPY 660 per transfer) and crypto network withdrawal fees, custody withdrawal fees, and per-deal commissions on IEO issuances. Hedging on the exchange side is executed through cover-trading relationships with SBI VC Trade, bittrade, and OKCoin Japan. The company's most differentiated product initiative is the NIDT (Nippon Idol Token) IEO, a 1,000,000,000-token issuance by affiliated Overse Inc., traded and custodied on the BACKSEAT platform alongside a weekly market-commentary publication cadence.

Following the February 20, 2025 acquisition of 100% of the company's shares by holding company BACKSEAT Inc. (JPY 800M stated capital including reserve, founded April 9, 2024), Coinbook was repositioned under new executive leadership (Chairman 林政泰, President 前田慶次), renamed to BACKSEAT Exchange Inc. on April 21, 2025, and migrated its primary domain to backseat-exchange.com. Registered capital including capital reserve was reported at JPY 2,327M as of April 30, 2026, indicating a meaningful post-acquisition balance-sheet expansion to support product, custody, and ecosystem investments. Operations remain exclusively domestic to Japan, with self-serve online onboarding, 24/7 smartphone access, and a dedicated OTC desk.

Name

Coinbook

Legal name

BACKSEAT暗号資産交換業株式会社

Website

https://coinbook.co.jp

Company type

Private

Founded year

2018

Operating status

Operating

Short description

Coinbook (BACKSEAT Exchange Inc.) is a Tokyo-registered Japanese cryptocurrency exchange operator offering spot trading (ADA/JPY, NIDT/JPY), OTC desk, staking, IEO, and custody services to retail and corporate clients, with 100% cold-wallet custody and Kanto Finance Bureau registration.

Ownership category

akta.pro rank

Product category

Cryptocurrency Exchange

NAICS

Securities and Commodity Exchanges (52321), Securities, Commodity Contracts, and Other Financial Investments and Related Activities (523), Financial Transactions Processing, Reserve, and Clearinghouse Activities (52232)

SIC

Security & Commodity Brokers, Dealers, Exchanges & Services (6200), Commodity Contracts Brokers & Dealers (6221), Finance Services (6199)

akta.pro industry

PRIMARYFSADAJAB

OTC Spot Trading & Block Execution

Financial & Insurance/Crypto & Digital Assets/Institutional Infrastructure (Prime Brokerage, OTC & Liquidity)

SECONDARYFSADAIAE

On/Off-Ramp Providers (Fiat↔Crypto) & Cash-In/Cash-Out Networks

Financial & Insurance/Crypto & Digital Assets/Payments, Merchant Acquiring & Remittances (Crypto)

SECONDARYFSACANAJ

Crypto-Digital Asset Market Making (Spot & Derivatives)

Financial & Insurance/Capital Markets & Securities/Market Making & Liquidity Provisioning

Keywords

• Cryptocurrency exchange
• OTC trading
• Crypto staking
• IEO platform
• Crypto custody

Headquarters

HQ city

Akasaka

HQ country

Japan

HQ region

Asia

Offices2 records

Markets served

GTM type

B2B and B2C

Offering type

Software

Cost components

Personnel, Technology or R&D, Operations, Marketing or Sales, Others

Revenue model

1. Exchange Trading Fees: Maker/taker fee model on the exchange service (ADA/JPY, NIDT/JPY trading pairs). Fee rate applied to traded amount.
2. Sales Office (OTC Sales) Spread: No explicit transaction fee is charged on sales office transactions; revenue is generated through the bid-ask spread between buy and sell prices.
3. OTC Transaction Fees: No trading fee charged; revenue derived from wire transfer and crypto transfer fees for deposits and refunds, plus spread on OTC pricing.
4. IEO Sales Commission: Fee charged on issuance and sale of new tokens through the IEO platform, disclosed per IEO offering.
5. Custody (Custodial) Service Fees: Fees charged on crypto asset withdrawals for custody service clients; no account management fees, annual fees, or deposit fees.
6. Japanese Yen Deposit/Withdrawal Fees: Fees charged for JPY deposits and withdrawals: free for deposits, JPY 330/inquiry for balance inquiries, JPY 660/transfer for withdrawals.
7. Crypto Asset Transfer Fees: Network fees charged for crypto asset deposits and withdrawals (deposits free; withdrawal fees vary by asset).

Pricing tiers

Go-to-market motion2 records

Distribution channels3 records

Marketing channels6 records

Core offering

Coinbook (now operating as BACKSEAT Exchange) operates a regulated Japanese cryptocurrency exchange offering retail spot exchange trading (ADA/JPY, NIDT/JPY), sales-counter simple buy/sell, OTC large-volume trading (JPY 5M–300M for BTC/ETH/ADA), staking services, IEO token issuance, and crypto asset custody on a unified online platform accessible 24/7 via web and smartphone. The company is a registered cryptocurrency exchange operator (Kanto Finance Director Registration No. 00026) and supports the proprietary Nippon Idol Token (NIDT) ecosystem.

Product overview

Coinbook operates as a cryptocurrency exchange platform offering multiple trading formats: a sales-counter service (販売所) for simple buy/sell transactions, a cryptocurrency exchange (取引所) for ADA/JPY and NIDT/JPY trading pairs, an OTC desk for large-volume transactions, staking services for earning blockchain rewards, IEO services for new token offerings, and custody services for asset safekeeping. The company also issued its own Nippon Idol Token (NIDT) through its IEO platform. The services are unified under the BACKSEAT暗号資産交換業 brand following a shareholder change and rebranding in April 2025.

Differentiator

Problem solved

Functional benefit

Products and services

• Cryptocurrency Sales Counter (暗号資産かんたん取引 / 販売所) A sales-counter service that allows customers to buy and sell cryptocurrency at company-set prices, designed for simple transactions; no transaction fees are charged, only withdrawal fees apply. Targets retail users seeking quick crypto purchases.
• Cryptocurrency Exchange (暗号資産取引所) A trading venue that matches buyers and sellers of cryptocurrency, supporting ADA/JPY and NIDT/JPY trading pairs, operating 24/7 with market and limit orders under a maker/taker fee model. Targets active retail and experienced crypto traders.
• Cryptocurrency OTC Trading (暗号資産OTC取引) Over-the-counter trading service where the company acts as the direct counterparty for large-volume transactions handled via phone or email. Supports BTC, ETH, ADA, and NIDT against JPY, with transaction sizes of JPY 5M–300M for BTC/ETH/ADA and JPY 500K–50M for NIDT. Targets corporate and institutional clients.
• Staking (ステーキング) A staking service that allows customers to earn rewards by committing their cryptocurrency holdings to blockchain validation processes, with rewards calculated daily at 9:00 AM based on the applicable annual rate. Customer assets are held 100% in cold wallets. Targets holders of supported crypto assets seeking passive yield.
• Initial Exchange Offering (IEO) An Initial Exchange Offering service in which the company acts as intermediary for new token fundraising, screening issuers and new tokens before offering them to customers at the offering price. Targets token issuers seeking distribution and investors seeking early-access tokens.
• Custody Service (カストディサービス) A custody service where the company holds and manages customer cryptocurrency assets in cold wallets, supporting BTC, ETH, ADA, and NIDT. No account management or annual fees are charged; only withdrawal fees apply. Targets customers and institutions seeking secure long-term asset safekeeping.
• Nippon Idol Token (NIDT) A proprietary token launched via IEO on the Coinbook platform, issued by Overse Inc., representing an entertainment/fan-token ecosystem tied to Japanese idol IP. Available for trading on the platform's NIDT/JPY pair.

Quantifiable outcome

• All customer crypto assets managed 100% in cold wallets with full segregation from company assets.
• +2 more outcomes

Segments2 records

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Six partnerships are on record, tiered core and minor.

• SBI VCトレード株式会社coreTechnology or IntegrationCover trading partner for the exchange's crypto asset trading services. One of the primary domestic cryptocurrency exchanges used for hedging customer trading positions.
• ビットトレード株式会社coreTechnology or IntegrationCover trading partner for the exchange's crypto asset trading services. Used as a counterparty for hedging customer trading positions.
• オーケーコイン・ジャパン株式会社coreTechnology or IntegrationCover trading partner for the exchange's crypto asset trading services. Used as a counterparty for hedging customer trading positions.
• SBIクリアリング信託株式会社coreOthersTrust company that holds customer JPY deposits via a client-classified trust (利用者区分管理信托). Customer JPY funds are managed separately from company funds through this fiduciary arrangement.
• 株式会社オーバース (Overse Inc.)coreStrategic or Co-development PartnerIssuer of Nippon Idol Token (NIDT) conducted via IEO on the BACKSEAT Exchange platform. BACKSEAT acted as the cryptocurrency exchange intermediary for the NIDT token issuance and sale.
• クリプトコラム (CryptoSpells)minorGTM or Marketing PartnerCryptoSpells media platform featured BACKSEAT Exchange (coinbook) in its 'Recommended Cryptocurrency Exchange' article, providing editorial media coverage.

Scale indicators3 records

Recent moves8 records

Expansion highlights5 records

Direct peers

• Coincheck: Major retail-focused Japanese crypto exchange, now under Monex Group, offering exchange, sales-counter, staking, and NFT services. Directly comparable multi-service Japan-licensed venue.
• SBI VC Trade: Crypto exchange arm of SBI Group; also a cover-trading counterparty for Coinbook. Operates a Japan-licensed spot exchange, staking, and IEO with strong institutional and retail reach.
• bitbank: Japan-licensed crypto exchange focused on spot trading and staking with a strong technical/pro trader user base. Competes with Coinbook for the same domestic regulatory-licensed retail flow.
• BITPOINT: Japan-licensed crypto exchange operated by Remixpoint, offering spot trading, OTC, and staking — a similarly positioned mid-tier domestic exchange with comparable product breadth.
• GMO Coin: Japan-licensed crypto exchange operated by GMO Internet Group, offering spot trading, OTC-style sales counter, and staking. Closely comparable product set and customer segments to Coinbook.
• bitFlyer: Japan's largest domestic crypto exchange, offering spot trading, OTC, staking, and custody under a JFSA registration — the same regulatory and product footprint Coinbook is pursuing at a smaller scale.

Broad incumbents

• Binance Japan: Japanese arm of global crypto exchange Binance, operating under local JFSA licensing. A much larger incumbent competing in the same domestic spot and OTC markets as Coinbook.

Regional players

• OKCoin Japan: Japan-focused crypto exchange that previously operated under the OKCoin brand (separate from global OKX); provides spot trading under Japanese licensing, comparable in scale and regulatory posture.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat5 records

Key risks5 records

Key highlights6 records

Customer concentration

• Xx.com/CoinBook_JP

Compliance7 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles14 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Coinbook