---
title: "Nippon Building Fund (NBF, J-REIT 8951)"
aliases:
  - "nippon-building-fund-j-reit-8951"
  - "Nippon Building Fund"
  - "NBF"
  - "NBF 8951"
  - "日本ビルファンド投資法人"
  - "Mitsui Fudosan office J-REIT"
  - "NBF office J-REIT"
  - "NBF 8951 Tokyo office"
domain: real-estate-finance
created: 2026-05-25
last_updated: 2026-07-29
last_tended: 2026-07-29
review_by: 2027-01-29
confidence: likely
tags: [real-estate-finance, j-reit, nbf, mitsui-fudosan, office, tokyo-cbd, 8951]
status: active
sources:
  - "https://www.nbf-m.com/"
  - "https://www.nbf-m.com/nbf/en/"
  - "https://www.nbf-m.com/nbf_e/"
  - "https://www.nbf-m.com/en/client/docs/investment.pdf"
  - "https://www.nbf-m.com/nbf_e/portfolio/list.html"
  - "https://www.nbf-m.com/nbf_e/portfolio/tenant.html"
  - "https://www.mitsuifudosan.co.jp/english/ir/"
  - "https://www.jpx.co.jp/english/markets/products/reit/index.html"
  - "https://www.ares.or.jp/en/"
  - "https://www.fsa.go.jp/en/"
---

# Nippon Building Fund (NBF, J-REIT 8951)

## TL;DR

**Nippon Building Fund Inc. (NBF, TSE J-REIT 8951)** is a Mitsui Fudosan-sponsored, office-specialized J-REIT and was one of the two first-listed J-REITs in September 2001. At 2026-07-01, its official portfolio page reported 69 properties and a ¥1,558.9 billion acquisition-price total; Tokyo's 23 wards represented 78.8% of that acquisition-price denominator. Current rank, index membership, sponsor-origin share and comparison with [[real-estate-finance/japan-real-estate-j-reit-8952|Japan Real Estate (JRE, 8952)]] must still be established from same-date issuer and index-provider data.

Tenant concentration depends on the contractual layer. NBF's [major-tenants disclosure](https://www.nbf-m.com/nbf_e/portfolio/tenant.html) at 2025-12-31 lists Mitsui Fudosan as tenant / master lessee for Shinjuku Mitsui Building and 23 other properties: **573,235 m2, or 47.0% of total rentable area**. Mitsui Fudosan generally subleases those properties to multiple end tenants, and NBF receives the sublease rent less a stated percentage. The 47.0% contractual counterparty concentration and the diversification of underlying occupants are therefore different measurements; neither should be replaced by an unsupported “mid-single-digit” claim.

## Wiki route

This entry sits under [[real-estate-finance/INDEX|real-estate-finance index]] as the **Mitsui Fudosan office J-REIT anchor**. Read it together with [[real-estate-finance/mitsui-fudosan-financing-model|Mitsui Fudosan financing model]] for sponsor-side financing and asset-recycling context, with [[real-estate-finance/japan-real-estate-j-reit-8952|Japan Real Estate (JRE, 8952)]] for a same-vintage office-J-REIT comparison, and with [[real-estate-finance/top-10-j-reit-overview-matrix|Top 10 J-REIT overview matrix]] for cross-J-REIT positioning. The structural-governance frame is [[real-estate-finance/j-reit-vs-us-reit-governance-comparison|J-REIT vs US REIT governance comparison]] and [[real-estate-finance/j-reit-sponsor-structure-conflict|J-REIT sponsor structure and conflict of interest]]. For office vs logistics contrast use [[real-estate-finance/logistics-j-reit-vs-office-j-reit-asset-class-comparison|logistics J-REIT vs office J-REIT asset-class comparison]] and the logistics anchors [[real-estate-finance/glp-j-reit-3281|GLP J-REIT (3281)]] and [[real-estate-finance/nippon-prologis-reit-3283|Nippon Prologis REIT (3283)]].

## 1. Corporate identity

Table evidence (reviewed 2026-07-29): [NBF investment-corporation structure](https://www.nbf-m.com/en/client/docs/investment.pdf), [NBF official disclosures](https://www.nbf-m.com/nbf_e/) and the [JPX listed-REIT directory](https://www.jpx.co.jp/english/equities/products/reits/issues/index.html).

| Item | Detail |
|---|---|
| Ticker | TSE J-REIT **8951** |
| Investment corporation | Nippon Building Fund Inc. (日本ビルファンド投資法人) |
| Asset-management company | Nippon Building Fund Management Ltd., under NBF's asset-management entrustment agreement |
| Sponsor | [[real-estate-finance/mitsui-fudosan-financing-model|Mitsui Fudosan]] (TSE Prime 8801) |
| Listing date | September 2001 (first-listed J-REIT alongside [[real-estate-finance/japan-real-estate-j-reit-8952|JRE]]) |
| Investment scope | Office-specialized portfolio; actual geographic exposure must use the dated portfolio denominator |
| Investment-corporation asset custodian and unitholder-register administrator | [[trust-banks/sumitomo-mitsui-trust|Sumitomo Mitsui Trust Bank, Limited]] |
| General administrators | Reiwa Accounting Holdings Co., Ltd. for accounting; PwC Tax Japan for tax affairs |
| Property-level trust trustee | A separate asset-level role for property held through trust beneficial interests; identify it only from the applicable property/title disclosure |
| Rating | Use the current ratings and outlooks disclosed by NBF and each rating agency |
| Index status | Verify current inclusion directly from each index provider's dated constituent list |

## 2. Portfolio composition

Table evidence (reviewed 2026-07-29; issuer snapshot as of 2026-07-01, occupancy as of 2026-06-30): [NBF official portfolio dashboard](https://www.nbf-m.com/nbf_e/). NBF disclosed **69 properties**, ¥1,558.9 billion asset size and 98.2% occupancy.

| Axis | NBF pattern |
|---|---|
| Asset class | Office-specialized, as stated by NBF |
| Geographic concentration | At 2026-07-01, Tokyo's 23 wards were 78.8% of total acquisition price; other Greater Tokyo was 7.9% and other cities 13.3% |
| Tokyo sub-market focus | Derive from the current property list using a stated denominator; do not infer it from the sponsor's wider territory |
| Property size and tenant structure | Calculate from current property and tenant data; the master-lease counterparty table is not an end-occupant census |
| Acquisition source | Classify each dated acquisition as sponsor / related-party or third-party from the transaction disclosure; sponsor redevelopment is not a committed pipeline |
| Property age | Calculate from the current property list using a stated weighting method |

## 3. Capital and leverage

Table evidence (reviewed 2026-07-29): [NBF official financial strategy and portfolio dashboard](https://www.nbf-m.com/nbf_e/). The issuer states an LTV target range of **36%–46%**; all point-in-time debt and DPU figures must use the applicable period disclosure.

| Item | NBF pattern |
|---|---|
| LTV policy band | Issuer target range **36%–46%** |
| Debt mix | Use NBF's current debt schedule for lenders, instruments, rates and maturities |
| Bond curve | Compare dated NBF bond terms with matched J-REIT issues; do not assume benchmark status |
| Sponsor support stake | Use NBF's dated major-unit-holder disclosure; do not substitute a typical sponsor percentage |
| Distribution policy | Fiscal periods end in June and December; tax deductibility is subject to statutory conduit conditions, including the applicable greater-than-90% distribution test |
| Foreign-investor share | Use NBF's dated unit-holder disclosure; JPX investor-type trading data measures flow, not issuer ownership |

## 4. Contractual master lessee vs end tenants

Table evidence (as of 2025-12-31): [NBF major tenants](https://www.nbf-m.com/nbf_e/portfolio/tenant.html).

| Measurement | Officially disclosed reading |
|---|---|
| Contractual tenant / master lessee | Mitsui Fudosan: Shinjuku Mitsui Building and 23 other properties |
| Leased area | **573,235 m2**, **47.0%** of NBF's total rentable area |
| Sublease structure | Mitsui Fudosan generally subleases the relevant properties to various sublessees; some leased space is excluded from that description |
| Rent mechanism | NBF receives the rents collected by Mitsui Fudosan from sublessees less a stated percentage |
| Next named tenant | Sony Group: **73,477 m2**, **6.0%** of total rentable area |

The official table measures NBF's contractual tenant exposure, so Mitsui Fudosan cannot be described as a minimal tenant. Analysis of end-occupant diversification requires a separate subtenant dataset and a clearly stated denominator. Contractual concentration, building-level multi-tenancy and DPU volatility are not interchangeable.

## 5. NBF vs JRE — same-vintage office-J-REIT comparison

Table evidence (reviewed 2026-07-29): [NBF official disclosures](https://www.nbf-m.com/nbf_e/), [JRE portfolio disclosures](https://www.j-re.co.jp/en_cms/portfolio/statement.html), and [JPX listing data](https://www.jpx.co.jp/english/equities/products/reits/issues/index.html). Sub-market labels are qualitative and should be checked against current property lists.

| Axis | NBF (Mitsui Fudosan) | JRE (Mitsubishi Estate) |
|---|---|---|
| Ticker | 8951 | 8952 |
| Sponsor | [[real-estate-finance/mitsui-fudosan-financing-model|Mitsui Fudosan]] | [[real-estate-finance/mitsubishi-estate-financing-model|Mitsubishi Estate]] |
| Listing date | September 2001 (first) | September 2001 (co-first) |
| Geographic exposure | Calculate from the same-date property lists using the same denominator | Calculate from the same-date property lists using the same denominator |
| Acquisition source | Classify dated transactions and read the current sponsor-support agreement | Classify dated transactions and read the current sponsor-support agreement |
| AUM scale | Compare same-date issuer figures | Compare same-date issuer figures |
| LTV | Use the current issuer definition and date | Use the current issuer definition and date |
| DPU yield | Align market price, DPU definition and date | Align market price, DPU definition and date |
| Foreign-investor profile | Use dated NBF unit-holder disclosure | Use dated JRE unit-holder disclosure |
| Sub-market exposure | Derive from NBF's current property list | Derive from JRE's current property list |

NBF and JRE provide a useful sponsor-model comparison. Do not infer pipeline contribution, valuation or sub-market sensitivity without same-date issuer data and the relevant agreements or transactions.

## 6. Counterpoints

- For sponsor dependence, calculate sponsor / related-party acquisitions over a stated period and apply the issuer's transaction controls.
- For office-demand resilience, compare dated vacancy, rent, lease expiry and tenant retention with a defined peer set.
- For yield attractiveness, align DPU, market price, tax, currency hedge, date and JGB tenor.
- For leverage, compare financing cost, maturity, covenant headroom and downside scenarios rather than labeling the LTV.
- For growth, use disclosed acquisition capacity and an identified pipeline; sponsor redevelopment alone is not a committed NBF acquisition.

## Related

- [[real-estate-finance/INDEX|real-estate-finance index]]
- [[real-estate-finance/mitsui-fudosan-financing-model|Mitsui Fudosan financing model]]
- [[real-estate-finance/japan-real-estate-j-reit-8952|Japan Real Estate (JRE, 8952)]]
- [[real-estate-finance/nomura-real-estate-master-fund-nmf|Nomura Real Estate Master Fund (NMF)]]
- [[real-estate-finance/glp-j-reit-3281|GLP J-REIT (3281)]]
- [[real-estate-finance/nippon-prologis-reit-3283|Nippon Prologis REIT (3283)]]
- [[real-estate-finance/top-10-j-reit-overview-matrix|Top 10 J-REIT overview matrix]]
- [[real-estate-finance/j-reit-market-overview|J-REIT market overview]]
- [[real-estate-finance/j-reit-vs-us-reit-governance-comparison|J-REIT vs US REIT governance comparison]]
- [[real-estate-finance/j-reit-sponsor-structure-conflict|J-REIT sponsor structure and conflict of interest]]
- [[real-estate-finance/j-reit-foreign-investor-ownership|J-REIT foreign investor ownership]]
- [[real-estate-finance/j-reit-dividend-yield-vs-jgb-spread|J-REIT dividend yield vs JGB spread]]
- [[real-estate-finance/logistics-j-reit-vs-office-j-reit-asset-class-comparison|logistics J-REIT vs office J-REIT comparison]]
- [[banking/trust-bank-custody-operating-comparison|trust bank custody operating comparison]]
- [[trust-banks/mitsubishi-ufj-trust-bank|MUFG Trust]] · [[trust-banks/sumitomo-mitsui-trust|SMTB]] · [[trust-banks/mizuho-trust-bank|Mizuho Trust]]
- [[INDEX|FinWiki index]]

## Sources

- NBF — official site, investment-corporation structure, portfolio and tenant disclosures.
- Mitsui Fudosan IR — https://www.mitsuifudosan.co.jp/english/ir/
- JPX — REIT Market English landing.
- ARES — Association for Real Estate Securitization, English.
- FSA — investment-corporation framework reference.