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S.BLOX Inc. — Japanese crypto-asset exchange operator overview

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Updated 2026-05-18
Review by 2026-08-08
Sources 6 Machine-translated Original (JA)
#fintech#jp-crypto-exchange#vasp#sony-group
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This entry sits under exchanges index. Read it with FSA crypto-asset exchange registration system — number system / Local Finance Bureau jurisdiction / registration requirements for adjacent context and Japan Financial Regulation — Legal Framework for Tokens, Crypto Assets, and Payments for the broader system boundary.

FSA registration number Kanto Local Finance Bureau 第00016号 · JVCEA member #1019 · registration date 2019-03-25

1. Corporate entity / shareholders

  • Trade name: S.BLOX Inc. (former trade names: Amber Japan, Inc.; DeCurret, Inc.)
  • English name: S.BLOX Inc.
  • Date established: 2018年1月10日
  • Head office location: 5-10号, Konan 2-chome, Minato-ku, Tokyo
  • Parent company: Quetta Web, Inc. (shareholding ratio 100%). Quetta Web is a subsidiary 100%-invested by Sony Group Corporation. The de facto ultimate parent is Sony Group Corporation (TSE Prime 6758).
  • Capital: 350,000,000円 (as of 2026年 per the official corporate site. As of 2024年7月 disclosure it was reported as 1,708,179,531円, and a capital reduction may have occurred since)
  • Listing: unlisted (the parent, Sony Group, is listed)

2. License / registration status

  • Crypto-asset exchange business: Director-General of the Kanto Local Finance Bureau 第00016号 (registration date 2019-03-25)
  • JVCEA member type: Type 1 member (membership number 1019). Crypto-asset exchange business only. No registration for crypto-asset derivatives business, electronic payment instruments business, or funds-transfer business (as of 2026-05-18).

3. Supported currencies

The brokerage (sales-outlet) coins listed on the official service site (as of 2026年5月) are the following 6:

  • BTC (Bitcoin)
  • ETH (Ethereum)
  • XRP (Ripple)
  • TRX (Tron)
  • BCH (Bitcoin Cash)
  • LTC (Litecoin)

The official site states that “further expansion is planned going forward.” BTC and ETH are major coins “traded domestically at 85% or more” (see the JVCEA FY 2022年 annual report). The altcoin lineup is at the industry’s smallest level, and at present the composition is centered on major currencies.

4. Scope of business

  • Spot trading (sales outlet): 6 coins such as BTC/ETH/XRP. Counterparty (spread) method.
  • Exchange (order-book trading): no public information (appears not offered as of 2026年5月).
  • Margin / derivatives: none (not registered for JVCEA crypto-asset derivatives business).
  • Fiat deposit channels: bank transfer. Deposit fees are announced as free after the service renewal. Details of quick deposit (convenience stores, etc.) are not disclosed.
  • NFT-related: conducted a Sony Group Soneium (blockchain) collaboration NFT campaign at 2025年 (Ghost in the Shell collaboration, etc.).
  • Minimum trade size: emphasizes support for small-lot investing. Lowered the minimum order quantity for bitcoin at 2026年3月.

5. Market share / trading volume

  • Number of accounts and monthly trading volume not disclosed (as of 2026年5月).
  • A small-scale operation with only 6 coins and brokerage-only, its industry position is classified as niche / small-scale. The scale gap versus major exchange operators such as bitFlyer, GMO Coin, and Coincheck is large.
  • After joining the Sony Group, it is seen to be exploring a user-acquisition strategy leveraging the parent’s brand power, but specific performance figures are not disclosed.

6. History / major events

  1. 2018年1月Established DeCurret, Inc. as an equity-method affiliate of Internet Initiative Japan Inc. (IIJ). Founded with a focus on digital-currency payment services.
  2. 2019年3月Crypto-asset exchange operator registration (Director-General of the Kanto Local Finance Bureau 第00016号). Began virtual-currency trading as the “DeCurret” service.
  3. 2021年12月Established DeCurret Holdings, Inc. and shifted to a holding-company structure.
  4. 2022年2月Succeeded the digital-currency business to DeCurret DCP, Inc. via an absorption-type split. On the same day, sold the remaining crypto-asset exchange business (exchange operation) portion to WhaleFin Holdings Japan, Inc., the Japanese entity of the Singapore-based market maker Amber Group (change of shareholder).
  5. 2022年9月Changed its company name to Amber Japan, Inc. The service name was also rebranded to “WhaleFin.”
  6. 2023年8月Quetta Web, Inc. (a subsidiary 100%-invested by Sony Group Corporation) acquired all shares of Amber Japan, joining the Sony Group. Lee Yijin, the Amber-era Representative Director, resigned, and Jun Watanabe, formerly of Sony Network Communications, became Representative Director and President.
  7. 2024年7月1日Changed its company name to S.BLOX Inc. Positioned as the crypto-asset exchange window in Sony Group’s Web 3 strategy.
  8. 2025年1月Completed the service renewal and changed the service name from “WhaleFin” to S.BLOX.

Regarding the relationship with TaoTao: TaoTao, Inc. (former Yahoo! Japan / Z Corp lineage) was merged into and absorbed by SBI VC Trade, Inc. at 2021年12月, and is a separate entity / separate lineage. It has no corporate-succession relationship whatsoever with S.BLOX (formerly DeCurret), and its FSA registration number differs.

7. Strategic developments

  • Soneium integration: publicly states integration with Soneium, a public blockchain developed by Sony Group as a joint venture of Sony Network Communications Labs and Startale Labs. As a crypto-asset exchange, it is expected to serve as the onramp function to NFTs and various Web 3 content.
  • NFT campaigns: continues to run collaborations with Sony Group’s IP and blockchain assets, such as the 2025年2月 “Ghost in the Shell NFT campaign” and the 2025年9月 “Soneium collaboration NFT campaign.”
  • Planned currency expansion: the official site previews the addition of more coins, but a specific timeline and coin names are undisclosed as of 2026年5月.
  • IPO developments: not disclosed. Operating as an unlisted subsidiary of its parent, the Sony Group.
  • Jun Watanabe (Representative Director and President): from Sony Network Communications. Reported to also serve concurrently as head of Sony G’s “Advanced Infrastructure Business Exploration Division” (Nikkei 2025年1月). Appointed upon completion of the 2023年8月 acquisition.
  • Lee Yijin (former representative): operated WhaleFin as the Japanese-entity representative of Amber Group. Resigned upon the 2023年8月 Sony acquisition.
  • IIJ (Internet Initiative Japan Inc.) (founding investor): the principal investor at DeCurret’s establishment. Has now exited from the shareholder roster.

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