Siiibo

What Siiibo does

Siiibo Securities Co., Ltd. operates a self-serve online platform in Japan for the issuance, distribution, and secondary trading of private placement corporate bonds (私募社債) targeted at retail investors. Founded January 11, 2019 by Kazuki Komura and headquartered in Tokyo's FinGATE TERRACE, the company holds a Type I Financial Instruments Business Operator registration (Kanto Local Finance Bureau No. 3230) and is a member of the Japan Securities Dealers Association, allowing it to underwrite, solicit, and intermediate securities. Its product surface includes individual private placement bonds (¥500K–¥3M per unit, 1–4 year maturity, 2–8%+ yen interest), puttable bonds (定期換金債), convertible bonds (転換社債) via J-Ships, a proprietary secondary market (セカンダリーマーケット) providing pre-maturity liquidity, and the Omatome Bond (おまとめ債) repackaged product bundling 5–20 underlying bonds.

The technology layer is a full-lifecycle platform: IR disclosure publishing, investor onboarding via eKYC in ~3 minutes, a distinctive "reverse-inquiry" matching engine (希望条件入力機能) where investors input desired interest rate/term/size per company and issuers select from aggregated demand, order management, secondary-market buyback, interest distribution, and redemption. The company serves two segments simultaneously — affluent Japanese individual investors (average financial assets ~¥100M, average age 42, 97% with listed-stock experience) seeking 2–8%+ yen yield, and mid-to-late-stage startups/unlisted companies seeking non-dilutive debt capital. Named issuers include C Channel, Eco-Pork, DFree, Varinos, TENTIAL, Lantrip, and Gojo & Company, totaling 40+ companies and 100+ bond issuances with cumulative volume of ~¥3B+ as of July 2025.

Revenue is transaction-based: issuance/distribution fees from corporate issuers, spread on secondary-market buybacks, and (since April 2025) yield from underwriting. Account opening and investor purchases are commission-free; the company generates the bulk of revenue on the issuer side. As of June 12, 2026, Metaplanet (TSE:3350) agreed to acquire 100% of Siiibo for ¥2.1B (~$13.1M) under 'Project Nova,' with closing expected July 13, 2026 and rebranding to Metaplanet Securities to develop Bitcoin-linked yield products.

Name

Siiibo

Legal name

Siiibo証券株式会社

Website

https://siiibo.com

Company type

Private

Founded year

2019

Operating status

Operating

Headcount range

11–50 employees

Short description

Siiibo Securities operates Japan's Type I-licensed online platform for retail-accessible private placement corporate bonds, using a reverse-inquiry matching engine and a proprietary secondary market to connect mid-to-late-stage startups and unlisted companies with affluent individual investors seeking 2–8%+ yen interest income.

Ownership category

akta.pro rank

Product category

Online Securities Brokerage (Private Placement Bonds)

NAICS

Investment Banking and Securities Intermediation (523150), Securities and Commodity Contracts Intermediation and Brokerage (5231)

SIC

Security Brokers, Dealers & Flotation Companies (6211)

akta.pro primary industry

IPO & New Issue Issuer Services (Listing/ISIN setup) (FSACAKAH)

akta.pro secondary industries

Agency & Supranational Bond Trading Platforms (FSAFACAD), Capital Markets Advisory (IPO Readiness, SPAC, ECM/DCM Advisory) (BPAHAOAL)

Keywords

• Private placement bonds
• Online securities platform
• Venture debt financing
• Bond investment platform
• Corporate bond issuance

Headquarters

HQ city

Tokyo

HQ country

Japan

HQ region

Asia

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

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

Revenue model

1. Bond Issuance and Distribution Fees: Siiibo charges issuers fees for private placement bond issuance support (underwriting and solicitation services). Revenue is generated when companies issue bonds through the platform, with the company having started underwriting services in April 2025 to increase issuance amounts available. Fees are embedded in bond terms or charged as a transaction fee on issuance volume.
2. Secondary Market Trading: When Siiibo buys back bonds from investors on the secondary market, it earns spread or transaction fees on the resale or hold.

Pricing tiers

Go-to-market motion1 record

Distribution channels1 record

Marketing channels5 records

Core offering

Siiibo Securities operates an FSA-licensed online platform enabling Japanese startups and unlisted companies to issue private placement corporate bonds (私募社債) directly to retail and individual investors. The platform manages the complete bond lifecycle — issuer screening and IR disclosure, investor onboarding via online eKYC, reverse-inquiry matching (investors input desired rate, maturity, and amount), subscription, secondary market liquidity via a platform-operated buyback/resale mechanism, and interest and redemption distribution. The company is a Type I Financial Instruments Business Operator (関東財務局長(金商)第3230号) and JSDA member, with related offerings including Omatome Bond (repackaged diversified bonds), Convertible Bonds via J-Ships, and Puttable Bonds.

Product overview

Siiibo Securities operates a unified online securities platform for private placement corporate bonds, connecting Japanese startups and mid-to-late-stage companies seeking debt financing directly with retail and institutional investors. The core offering is the Siiibo platform, which facilitates the issuance, purchase, and management of private placement bonds (私募社債). Key products include the Omatome Bond (おまとめ債) for diversified repackaged bond investments, and a Secondary Market (セカンダリーマーケット) for early redemption and liquidity. The platform also supports convertible bonds and provides IR information services for issuing companies. As a Type I Financial Instruments Business Operator, the company was acquired by Metaplanet in July 2026 and rebranded as Metaplanet Securities to develop Bitcoin-linked yield products under Project Nova.

Differentiator

Problem solved

Functional benefit

Products and services

• Siiibo Securities Online Platform (私募社債オンラインプラットフォーム) The proprietary online platform for private placement corporate bond issuance, subscription, secondary trading, and lifecycle management in Japan. Serves individual investors (retail accounts opened in ~3 minutes via online eKYC) and corporate issuers (startups/unlisted companies) requiring a Type I Financial Instruments Business Operator license and JSDA membership.
• Omatome Bond / Repackaged Bonds (おまとめ債) A diversified bond product that repackages 5–20 underlying individual corporate bonds into a single offering, allowing retail investors to achieve multi-issuer exposure with a single purchase and zero commission. Suited to investors who find single-bond selection burdensome and want built-in risk diversification.
• Private Placement Bonds (私募社債) Bonds issued to fewer than 50 specified investors through the Siiibo platform, designed for mid-to-late-stage Japanese startups and emerging-market listed companies seeking direct financing without equity dilution, bank covenants, or complex structured products. Investors earn 2–8%+ yen-denominated interest over 1–4 year maturities with ¥500,000–¥3,000,000 minimum units.
• Puttable Bonds (定期換金債, formerly 定期社債) Corporate bonds issued with periodic early-redemption options, allowing investors to either hold the bond for interest income or redeem early at predetermined dates with accrued interest payments. Designed for investors who want flexibility around reinvestment timing.
• Convertible Bonds (転換社債) Bonds offering a conversion option into the issuer's stock at predetermined conditions, offered to specified investors via the J-Ships system. Provides growth-equity-style upside through a debt instrument for investors who want exposure to issuer equity appreciation.
• Secondary Market (セカンダリーマーケット) Platform-operated secondary trading service providing liquidity for private placement bonds. Siiibo buys back bonds from investors seeking to exit before maturity and resells them to new investors, addressing the historic illiquidity of private placement bonds.
• Bond Underwriting Service (引受業務) Bond underwriting service launched in April 2025 allowing Siiibo to take principal positions in issued bonds, increasing the amount issuers can raise and the breadth of offerings available to investors on the platform.
• IR Information Service (IR情報サービス) Investor relations information platform for companies listing bond offerings on Siiibo, providing investors with financial data and business information to support due diligence and investment decisions.

Quantifiable outcome

• Cumulative bond issuance of 3 billion+ yen across 40+ companies and 100+ issuances
• +3 more outcomes

Named customers9 records

Segments1 record

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration2 records

Feature3 records

Partnerships

Seven partnerships are on record, tiered minor.

• スピカコンサルティング (Spica Consulting)minorChannel Partner/ Reseller/ Distributor · 16 October 2024Siiibo entered into a partnership with Spica Consulting, an M&A intermediary, to expand its issuer sourcing network. Spica Consulting refers companies seeking alternative financing to Siiibo's bond issuance platform, enhancing deal flow for Siiibo.
• IFA法人Japan Asset ManagementminorChannel Partner/ Reseller/ Distributor · 1 February 2024Siiibo partnered with independent financial advisor (IFA) Japan Asset Management to expand its distribution reach to investors through financial advisory channels. IFA recommends Siiibo's bond investment platform to their clients.
• Relic Inc.minorStrategic or Co-development Partner · 24 October 2023Siiibo entered into a capital and business partnership (資本業務提携) with Relic, a startup ecosystem and innovation platform. The partnership aims to co-develop new financial products and expand the issuer/investor ecosystem.
• FAMORE (IFA)minorChannel Partner/ Reseller/ Distributor · 6 March 2023Siiibo partnered with IFA firm FAMORE to expand investor reach through financial advisory distribution.
• アセット・デザイナーズ (Asset Designers, IFA)minorChannel Partner/ Reseller/ Distributor · 28 February 2023Siiibo partnered with IFA firm Asset Designers to expand investor reach through financial advisory distribution.
• ADワークスグループ (AD Works Group CVC)minorStrategic or Co-development Partner · 26 August 2022Siiibo began collaboration with AD Works Group's corporate venture capital (CVC) arm, linking startup issuers with investment opportunities through the CVC's network.
• 400F Inc. (亡くすけない, お金の身体健康診断)minorGTM or Marketing Partner · 16 August 2022Siiibo partnered with 400F, operator of the 'Financial Health Check' service, to cross-promote services and reach financially health-conscious consumers who may be interested in bond investment.

Scale indicators7 records

Recent moves10 records

Expansion highlights6 records

Direct peers

• Funds (ファンズ, Funds Inc.): Japanese online retail investment platform focused on private placement and loan-based products for individual investors. Most direct competitor to Siiibo in private debt/fund intermediation to Japanese retail, with overlapping reverse-inquiry-style matching and similar yen-denominated yield targets.
• Crowdcredit (クラウドクレジット): Japanese alternative investment platform offering retail investors access to private loans and overseas debt instruments. Comparable in retail-yield-product intermediation and online self-serve onboarding, though focused on cross-border lending rather than domestic private placement bonds.

Broad incumbents

• SBI Securities (SBI証券): Largest Japanese online broker with full Type I license, broad retail investor base, and growing presence in corporate bond and structured product distribution. A scaled incumbent that could expand into Siiibo's niche private placement bond space via brand and balance sheet.
• Monex Securities (マネックス証券): Major Japanese online broker offering retail bond, ETF, and alternative investment products. Comparable in that it offers online securities accounts to affluent retail investors with a similar GTM motion; broader product breadth than Siiibo.
• Rakuten Securities (楽天証券): Top Japanese online broker combining commission-free trading, retail bond distribution, and ecosystem distribution through Rakuten Group. Could replicate Siiibo's online onboarding if it expands private placement bond sourcing.
• Aozora Bank (あおぞら銀行): Japanese mid-tier commercial bank with a dedicated CVC (Aozora Corporate Investment) that took a strategic stake in Siiibo. Comparable on Japanese private placement bond market participation and as an institutional counterparty; broader finance and lending scope.

Emerging players

• Owner's Book (オーナーズブック): Japanese online alternative investment platform offering retail access to private real-estate debt and equity. Niche like Siiibo but focused on real estate rather than corporate bonds; comparable on the retail alternative-investor funnel mechanics.
• Securitize Japan: Provider of digital securities issuance and trading infrastructure globally, with activity in Japan for tokenized private securities. Comparable on technology-driven private placement distribution and retail-investor accessibility to alternative debt instruments.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• YouTubeyoutube.com/channel/UCsvPwh6H7TetRvpz-dXKTWw
• Xx.com/siiibo

Compliance5 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles3 records

Funding overview

Funding rounds4 records

Investors10 records

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

M&A

Investments9 records

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

Frequently asked questions about Siiibo