Custody Bank of Japan operating model
On this page
- Wiki route
- TL;DR
- 1. Institutional position
- Shareholder structure (public disclosure, as of 2020-07-27)
- Why two specialist custodians, not one
- Lineage diagram
- Business-line map
- Operating-function breakdown
- The 「信託口」 nominee surface — CBJ specific
- vs MTBJ — operating-detail comparison
- vs full-service trust banks
- vs global custodians
- 4. Fees and revenue structure
- Why CBJ fee economics resemble MTBJ closely
- Cross-bank fee-economy reading
- Regulatory stack
- Accounting treatment
- Merger-accounting note
- 6. JASDEC / clearing infrastructure connection
- Direct JASDEC participation
- JSCC + DVP
- BoJ JGB book-entry
- Foreign-asset sub-custody chain
- Related
- Sources
Wiki route
This entry sits under banking index. Read it with the entity anchor Custody Bank of Japan (CBJ), the operating peer Master Trust Bank operating model and entity MTBJ, the landscape summary Japan master trust and custody bank landscape, the cross-camp matrix Japan trust bank vs global custodian comparison matrix, and the operating comparison trust-bank custody operating comparison. Pair it with JASDEC and JSCC for the settlement-infrastructure side, with Japan banking license tier comparison matrix for the regulatory tier, with the shareholder-side trust-bank pages SMTB and Mizuho Trust, and with Japan listed financial groups investable universe for the institutional context.
TL;DR
The Custody Bank of Japan (CBJ — 日本カストディ銀行) is the other half of Japan’s two-strong asset-administration utility, formed by the 2020-07-27 merger of JTSB (日本トラスティ・サービス信託銀行) and TCSB (資産管理サービス信託銀行). Its shareholder camp is the Sumitomo Mitsui Trust Group (33.3%) + Mizuho FG (27.0%) + Resona Bank (16.7%) + Dai-ichi Life (8.0%) + life-insurer (Asahi / Meiji Yasuda / Japan Post Insurance / Fukoku) axis — distinct from MTBJ’s MUFG Trust + Nippon Life + Meiji Yasuda + Norinchukin camp. Operationally CBJ does the same work as MTBJ: pension trust administration, securities-investment-trust administration, and securities custody — under the dual 銀行法 + 信託業法 license route, with direct JASDEC + BoJ JGB settlement participation. Its 「日本カストディ銀行（信託口）」 nominee name appears at the top of every TOPIX issuer’s shareholder register alongside MTBJ’s. The 2020 merger consolidated two duplicate systems into one mandate base and was driven by the same passive-fund growth and pension-asset scale that produced MTBJ. CBJ + MTBJ together account for the majority of Japan’s institutional custody volume.
1. Institutional position
| Field | CBJ |
|---|---|
| Legal name (JA) | 株式会社日本カストディ銀行 |
| Legal name (EN) | Custody Bank of Japan, Ltd. |
| Established | 2020-07-27 (JTSB + TCSB merger) |
| HQ | 東京都中央区晴海 1-8-12 晴海アイランドトリトンスクエア オフィスタワー Z |
| License route | 銀行法 + 信託業法 (custody-only 信託銀行 / 信託兼営銀行) |
| Listing | Non-listed (multi-FG joint venture) |
| Primary regulator | 金融庁 (FSA) |
| Industry body | 信託協会 (Trust Companies Association of Japan) |
| Functional position | Asset-administration specialist (no loans, no PB, no real-estate trust, no inheritance trust) |
| Public AUC anchor | Approximately ¥696 trillion total assets under custody (受託信託財産 + 常任代理契約等に基づく預り資産; of which 信託財産 ¥476tn) as of 2025-03-31 |
| Peer | [[trust-banks/master-trust-bank |
Shareholder structure (public disclosure, as of 2020-07-27)
| Shareholder | Stake | Reading |
|---|---|---|
| [[trust-banks/sumitomo-mitsui-trust | 三井住友トラストグループ (SMTH)]] | 33.3% |
| [[megabanks/mizuho-fg | みずほフィナンシャルグループ (Mizuho FG)]] | 27.0% |
| りそな銀行 (Resona Bank) | 16.7% | Third-largest shareholder; legacy 大和 / あさひ信託 trust lineage in TCSB camp |
| [[life-insurers/dai-ichi-life | 第一生命保険]] | 8.0% |
| 朝日生命保険 | 5.0% | Life-insurer shareholder (legacy TCSB) |
| 明治安田生命保険 | 4.5% | Life-insurer shareholder |
| かんぽ生命保険 | 3.5% | Life-insurer shareholder |
| 富国生命保険 | 2.0% | Life-insurer shareholder (legacy TCSB) |
Why two specialist custodians, not one
The 2020-07 merger consolidated JTSB and TCSB but stopped short of merging with MTBJ. The public reading is:
- Shareholder politics — the MUFG / 生保 axis vs the SMTB / Mizuho / Resona / 生保 axis would not consolidate easily without ceding control;
- Risk concentration — Japan’s institutional asset-administration cannot rely on a single utility (operational risk + counterparty risk + 議決権 集中);
- Cost arbitrage — duplicate systems within each camp (JTSB vs TCSB inside the SMTB / Mizuho camp) were redundant, but inter-camp duplication produces a competitive check.
The 2020 merger achieved the intra-camp consolidation. Inter-camp consolidation (CBJ + MTBJ) remains an open question.
Lineage diagram
SMTB / 第一生命 lineage
日本トラスティ・サービス信託銀行 (JTSB) — 2000 設立
├── 旧中央三井信託 → SMTB
├── 旧住友信託 → SMTB
└── 第一生命
Mizuho / Resona / 生保 lineage
資産管理サービス信託銀行 (TCSB) — 2004 設立
├── みずほ信託 (Mizuho Trust)
├── りそな銀行 (旧 大和 / あさひ信託 系統)
├── Asahi Life, Meiji Yasuda, Japan Post Insurance, Fukoku Life
└── 旧第一勧業富士 / 安田信託 系統
↓ 2020-07-27 merger
日本カストディ銀行 (CBJ) — 株主 (2020-07-27 現在)
├── 三井住友トラストグループ (SMTH) 33.3%
├── みずほ FG (Mizuho FG) 27.0%
├── りそな銀行 (Resona) 16.7%
├── 第一生命 8.0%
└── 朝日生命 5.0% / 明治安田 4.5% / かんぽ生命 3.5% / 富国生命 2.0%Business-line map
| Segment | Core function | Typical client base | What it is not |
|---|---|---|---|
| 信託カストディ (Securities custody) | Safekeeping of equities, JGB, corporate bonds, foreign securities; book-entry registration; corporate-actions processing; dividend / interest receipt; tax reclaim ops | Pension plans, asset managers, life insurers, foreign global custodians needing a Japan sub-custodian | Not a proprietary investor; 「信託口」 nominee label is a recordkeeping construct |
| 年金信託 (Pension trust administration) | Trust contract for 厚生年金基金, DB, DC plans — recordkeeping, asset-owner reports, benefit-payment ops | GPIF, large corporate DB plans, DC plan administrators | Not the investment manager |
| 投信受託 (Securities-investment-trust admin) | Trust contract for 公募投信 / 私募投信 — fund accounting, NAV calc, holdings register, distribution processing | Asset managers using CBJ as 受託会社 (notably SMTB AM affiliates, Mizuho AM, Resona AM affiliates) | Not the fund manager or distributor |
| 特定金銭信託 (特金) ops | 特金 vehicles for institutional / corporate investors | Insurers, corporates, regional banks | Not a discretionary asset manager |
| 資産管理サービス (Master custody) | Institutional master-custody, multi-mandate consolidation, investment-instruction processing | Large multi-mandate asset owners | Not the sponsor |
Operating-function breakdown
| Function | Description |
|---|---|
| Safekeeping & book-entry admin | Direct connection to [[securities/japan-securities-depository-center |
| Settlement (cash equity) | DVP-X1 / DVP-X2 / DVP-X3 settlement via JASDEC + JSCC clearing |
| Settlement (JGB) | Direct participation in BoJ JGB book-entry system |
| Settlement (corporate bond / CP) | Book-entry transfer via JASDEC for 社債 and CP |
| Fund accounting / NAV calculation | Daily NAV calculation for 投信 mandates; 投信協会 standards |
| Corporate actions | Dividend / interest receipt, splits, rights offerings, conversions; foreign-asset CA via global custodian sub-network |
| Voting operations | Mechanical execution of asset-owner / manager instructions; ICJ electronic-voting forwarding |
| Sub-custody for foreign assets | Re-routing via [[foreign-financial-institutions/bny-mellon-japan |
| Member / participant ops | Pension member balance reporting (DB / DC), benefit-payment ops |
| Securities-lending support | Lending program admin (when client opts in); collateral posting; recall management |
The 「信託口」 nominee surface — CBJ specific
CBJ’s nominee name 「日本カストディ銀行（信託口）」 appears in the top-shareholder rows of substantially every TOPIX-100 issuer, often as 2nd or 3rd after MTBJ’s 「信託口」. The pattern is:
| Reading | Interpretation |
|---|---|
| Legal record name | CBJ |
| Beneficial owners | SMTB-side asset managers, Mizuho-side asset managers, Resona-side asset managers, 第一生命 separate accounts, Asahi / Meiji Yasuda / Fukoku Life accounts, foreign sub-custody clients of CBJ |
| Voting instruction source | Upstream asset manager or asset owner — not CBJ |
| Underlying exposure type | Largely passive index + active pension mandates + 投信 holdings |
vs MTBJ — operating-detail comparison
| Field | CBJ | MTBJ |
|---|---|---|
| Established | 2020-07-27 (JTSB+TCSB merger) | 2000-05 (greenfield) |
| Shareholder camp | SMTH 33.3% + Mizuho FG 27.0% + Resona 16.7% + 第一生命 8.0% + 朝日 / 明治安田 / かんぽ / 富国 生保 | MUFG Trust + Nippon Life + Meiji Yasuda + Norinchukin |
| Lead shareholder stake | 三井住友トラストグループ (SMTH) 33.3% | MUFG Trust 46.5% |
| Public AUC anchor | ~¥696tn (2025-03-31; total assets under custody) | ~¥770tn (2025-03-31; 管理資産残高) |
| HQ location | 東京都中央区晴海 | 東京都港区浜松町 |
| Legal-structure license | 銀行法 + 信託業法 (custody-only) | 銀行法 + 信託業法 (custody-only) |
| Loans / deposits | None / minimal | None / minimal |
| 不動産信託 | No | No |
| Inheritance / 相続 trust | No | No |
| PB / wealth | No | No |
| Real-estate trust | No | No |
| JASDEC direct | Yes (high volume) | Yes (high volume) |
| BoJ JGB direct | Yes | Yes |
| JSCC direct | Yes | Yes |
| ICSD (Euroclear / Clearstream) direct | No (re-routed via globals) | No (re-routed via globals) |
| GPIF custodian use | Yes (one of the resource pool) | Yes (one of the resource pool) |
| Listing | Non-listed | Non-listed |
vs full-service trust banks
| Dimension | CBJ | Megabank full-service trust banks (MUFG Trust / SMTB / Mizuho Trust) |
|---|---|---|
| Custody / 投信受託 | Core function (utility-scale) | Run internally + often delegate processing to CBJ / MTBJ |
| Real-estate trust | No | Major business line (RE securitization, J-REIT) |
| 相続 / 遺言 / PB | No | Yes — significant wealth-management revenue |
| 不動産信託 + 信託受益権 (J-REIT) | No | Yes — full processing |
| Securities agency (株式事務代行) | No | Yes |
| Pension front-office (運用提案) | No | Yes |
| DC service window | Limited (admin only) | Front office + admin |
CBJ does the processing while its trust-bank shareholders do the client relationship + front-office mandate. This vertical split is intentional and is the reason the trust-bank shareholders have not absorbed CBJ back into their consolidated operations.
vs global custodians
| Dimension | CBJ | Global custodians (BNY Mellon / State Street / JPM / Citi Japan) |
|---|---|---|
| Primary asset universe | Domestic Japan assets | Cross-border + foreign-investor JP sub-custody |
| ICSD connectivity | Indirect (via globals) | Direct |
| Voting administration | Yes (mechanical, ICJ-linked) | Yes (via Broadridge etc.) |
| Pricing power on JP custody | High (utility scale) | Medium (sub-custody premium) |
| Pricing power on foreign custody | Low (sub-rolled to globals) | High |
| Regulatory base | FSA only | FSA + home-country regulator (FRB / OCC / ECB / PRA) |
| G-SIB status | No | All four parents are G-SIBs |
4. Fees and revenue structure
CBJ does not publicly disclose detailed fee schedules. The public-domain reading is:
| Revenue line | Pricing basis | Public visibility |
|---|---|---|
| Pension trust administration fee | AUC bps (very low at GPIF / large-DB scale) | Not disclosed at line-item level (CBJ publishes no detailed fee schedule) |
| 投信受託 admin fee | AUC bps — 0.01-0.05% / year of NAV typical | Disclosed per fund in 信託約款 |
| Securities custody fee | AUC bps per asset class + per-ticket settlement fees | Not publicly disclosed |
| Voting / CA admin | Typically bundled into custody fee | Not separately disclosed |
| Securities-lending agent fee | Revenue share with beneficial owner | Not separately disclosed |
| Cash-balance interest income | Low | Not separately disclosed |
Why CBJ fee economics resemble MTBJ closely
Both run the same product set against similar mandate scales. Their fee pricing is anchored by:
- GPIF tender pressure — GPIF runs periodic 資産管理機関 panels where CBJ and MTBJ both compete; both incumbent-priced and challenger-priced.
- Passive-fund AUM growth — passive index funds have driven up CBJ-administered AUC while pushing down per-bp fees, producing volume-up / margin-down dynamics.
Cross-bank fee-economy reading
For granular MTBJ + CBJ + megabank trust-arm + global-custodian fee comparison see trust bank fee structure comparison.
| Aspect | CBJ | MTBJ |
|---|---|---|
| Pricing power vs asset managers | High (utility scale) | High (utility scale) |
| Pension trust admin fees trend | Stable to slightly compressing on large mandates | Same |
| Foreign-asset custody | Pass-through cost from globals | Pass-through cost from globals |
| Cost-side scale | High fixed-IT cost; per-mandate marginal cost very low | Same — both run utility economics |
Regulatory stack
| Layer | Statute / regulator | CBJ implication |
|---|---|---|
| Bank supervision | 銀行法 + 金融庁 監督指針 (信託兼営銀行 section) | Capital adequacy + governance + IT-risk; CBJ runs a light credit book and consequently a light capital ratio relative to AUC |
| Trust-business supervision | 信託業法 + 金融庁 監督指針 (信託業 section) | Trust account separation, fiduciary duty, conflict-of-interest controls |
| Securities-law overlay | 金融商品取引法 — 投信受託会社 / カストディ ops | NAV calc, custody standards, 投信協会 compliance |
| Pension regulation | 厚生年金保険法, 確定給付企業年金法, 確定拠出年金法 | DB / DC administration, fiduciary reporting |
| Deposit insurance | 預金保険機構加盟 | Statutory membership; minor relevance given small deposit base |
| AML / CFT | 金融庁 + 警察庁 + 国税庁 reporting | Custody-side AML applied at underlying client level |
| Stewardship / governance | スチュワードシップ・コード (voluntary) | Voting-admin transparency; CBJ executes per client instruction |
| Data / personal info | 個人情報保護法, 金融分野ガイドライン | Pension member data, NISA data |
Accounting treatment
| Item | Treatment |
|---|---|
| Trust assets (信託財産) | Off-balance-sheet at CBJ; on-balance at beneficial owner |
| Custody / admin fees | Recognized as fee income in P&L |
| Own-account deposits | On-balance-sheet — small |
| Settlement-account residuals | Short-duration; cash + due-from-banks |
| Goodwill / merger accounting (2020) | Recognized on JTSB + TCSB merger; specifics in shareholder consolidated disclosure |
Merger-accounting note
The 2020-07-27 JTSB + TCSB merger involved system integration over multiple years; integration costs flowed through CBJ P&L and were absorbed by shareholder parents in their consolidated trust-bank operating segments. The granular cost recovery and IT-write-down profile is not publicly disclosed (CBJ is non-listed and reports only summary figures; merger goodwill specifics sit in shareholder-parent consolidated disclosure).
6. JASDEC / clearing infrastructure connection
┌─────────────────────────────────────────────────────────────────┐
│ Beneficial owners (GPIF / corporate pensions / 投信 / insurers) │
└─────────────────────────────┬───────────────────────────────────┘
│ mandate
▼
┌─────────────────────────────────────────────────────────────────┐
│ Asset managers (front-office discretion + voting opinion) │
│ — SMTB AM affiliates, Mizuho AM, Resona AM, etc. │
└─────────────────────────────┬───────────────────────────────────┘
│ instruction
▼
┌─────────────────────────────────────────────────────────────────┐
│ Custody Bank of Japan (trust account / nominee) │
│ — recordkeeping, NAV, CA processing, voting admin │
└─┬────────────┬────────────┬───────────────┬────────────────────┬─┘
│ │ │ │ │
▼ ▼ ▼ ▼ ▼
┌───────────┐┌─────────────┐┌──────────────┐┌──────────────────┐┌─────────────────┐
│ JASDEC ││ JSCC ││ BoJ JGB ││ Global custodians│ │ ICJ voting plat.│
│ (equities,││ (CCP for ││ book-entry ││ for foreign sub- │ │ (electronic │
│ 社債, CP, ││ cash equity)││ (JGB ││ custody │ │ proxy voting) │
│ 投信) ││ ││ settlement) ││ │ │ │
└───────────┘└─────────────┘└──────────────┘└──────────────────┘└─────────────────┘Direct JASDEC participation
CBJ is a direct participant in:
- 株式振替制度 (dematerialized listed shares)
- 一般債振替制度 (corporate bonds: 普通社債, 転換社債)
- 短期社債振替制度 (CP)
- 投資信託振替制度 (publicly offered 投信 units)
JSCC + DVP
CBJ’s cash-equity settlement runs through JSCC as the central counterparty, producing DVP-X1 / X2 / X3 quality settlement. JSCC also runs CCP services for repos and OTC derivatives — CBJ’s exposure to these layers depends on individual client mandate scope.
BoJ JGB book-entry
CBJ holds a direct account in the BoJ JGB book-entry system, supporting DVP JGB settlement for pension and 投信 mandates without intermediate sub-custody.
Foreign-asset sub-custody chain
For non-JP assets in CBJ-administered mandates:
CBJ (record-name trust-account)
→ Global custodian (BNY / State Street / JPM / Citi)
→ Local sub-custodian in foreign market
→ Local CSDRelated
- INDEX
- japan-master-trust-and-custody-bank-landscape
- japan-trust-bank-custody-map
- japan-trust-bank-vs-global-custodian-comparison-matrix
- trust-bank-custody-operating-comparison
- master-trust-bank-operating-model
- jasdec-settlement-operations
- trust-bank-fee-structure-comparison
- pension-trust-mandate-allocation-japan
- japan-banking-license-tier-comparison-matrix
- custody-bank
- master-trust-bank
- sumitomo-mitsui-trust
- mizuho-trust-bank
- mitsubishi-ufj-trust-bank
- dai-ichi-life
- bny-mellon-japan
- state-street-japan
- jpmorgan-japan
- citigroup-japan
- japan-securities-depository-center
- japan-securities-clearing-corp
- japan-market-infrastructure-map
- japan-listed-financial-groups-investable-universe
Sources
- Custody Bank of Japan: official site, about us, business explanation, corporate information page, English corporate page.
- 三井住友信託銀行「スケールメリットの追求」資産管理業務ページ（CBJ AUC: 総預かり資産 約696兆円 / 信託財産 476兆円、2025-03-31）— https://www.smtb.jp/business/instrument/management/scale
- 日本マスタートラスト信託銀行 2024 年度決算（MTBJ 管理資産残高 約770兆円、2025-03-31）— https://www.mastertrust.co.jp/assets/pdf/financial/zm20250521.pdf
- Trust Companies Association of Japan: trust-assets-under-management statistics.
- FSA: trust-business financial institution list, bank license list.
- JASDEC: securities book-entry and depository system materials.
- JSCC: clearing and DVP cash-equity materials.
- BoJ: JGB book-entry settlement system materials.
- Wikipedia (cross-reference): 株式会社日本カストディ銀行, JTSB, TCSB historical entries. — CBJ 株主構成（2020-07-27 現在）：三井住友トラストグループ 33.3% / みずほ FG 27.0% / りそな銀行 16.7% / 第一生命 8.0% / 朝日生命 5.0% / 明治安田生命 4.5% / かんぽ生命 3.5% / 富国生命 2.0%。https://ja.wikipedia.org/wiki/日本カストディ銀行 （2026-05-30 確認。旧版の「SMTB ~46.5% / Mizuho ~27% / Daiwa-affiliated」の出資者表記を訂正。46.5% は日本マスタートラスト信託における MUFG 信託の比率の誤転記、Daiwa Securities は CBJ の株主ではなく正しくは りそな銀行 16.7%）