Koto Ward sits east of central Tokyo, straddling the old industrial waterfront and some of the city's most photographed neighborhoods. Investors who treat it as a single market will miss the point entirely. Our analysis of 9,668 sales transactions and 19,740 rent listings in Koto reveals a gross yield range that runs from 8.9% down to 1.8%, depending on which station you pick. The ward median GRM is 264.6x monthly (4.54% yield), but that number hides more than it reveals.
This article breaks down what the data actually shows.
The Headline Number Most Investors Will Miss
The best yield in Koto belongs to Shinonome station, not the trendy neighborhoods foreigners read about online. A 2LDK unit within 7 minutes of Shinonome, built roughly 12 years ago, transacts at a median GRM of 134.6x monthly. That is a documented 8.9% gross yield on properties averaging around ¥80.5 million, backed by 52 sales transactions and median rents of ¥598,000 per month.
To put that in context: a GRM of 134.6x monthly is the kind of number that shows up in outlying wards or post-industrial cities, not in a ward 20 minutes by metro from central Tokyo. Shinonome is a reclaimed waterfront area, largely residential towers with young stock, sitting between the Rainbow Bridge and the Shin-kiba logistics zone. It is not a lifestyle destination. That is exactly why the price has not been bid up.
Minami-sunamachi, a quieter commercial strip along the Shuto Expressway, produces a comparable result in a different format. A 3LDK at Minami-sunamachi with 10 minutes on foot, at 41 years of building age, registers a GRM of 135.1x (8.9% yield) on 7 sales at ¥29.7 million. The age is the trade-off: older stock at lower prices, renting for ¥220,000 per month. For investors who have dealt with pre-1981 structures in Japan and understand the seismic compliance framework, this segment is a known trade-off.
Higashi-ojima, a few stops southeast on the Shinjuku Line, appears four times in the top performers list. The 2LDK entry closest to the station (3 minutes) produces a GRM of 150.8x (8.0% yield) at ¥31.7 million, with 40-year-old buildings. The 3LDK entries cluster between 151x and 164x, depending on building age and distance. This is a functioning micro-market with real volume.
Where the Yield Collapses: Kiyosumi-Shirakawa and Toyosu
The worst yield in Koto is not in an obscure corner of the ward. It is at Kiyosumi-Shirakawa, one of the most written-about neighborhoods in Tokyo real estate content targeting international audiences. A 1LDK within 1 minute of the station, at 51 years of building age, transacts at a GRM of 657x monthly. That is a 1.8% gross yield. The properties are averaging ¥51.6 million against median rents of ¥78,500 per month.
The math here requires explanation. Kiyosumi-Shirakawa has been aggressively marketed as a creative hub, third-wave coffee destination, and international-friendly enclave. That positioning has driven purchase prices into territory that rental demand has not followed. Buyers are paying for the postcode. Tenants are not paying a proportionate premium. A 657x GRM is not an investment thesis.
Toyosu produces a comparable problem at a higher price point. A 1LDK at Toyosu station, 6 minutes on foot, 19 years old, clears a GRM of 575x (2.1% yield) at ¥98.75 million. Toyosu is Tokyo's highest-volume station in this dataset with 2,272 transactions and a median price of ¥83 million. High liquidity is real here. But high liquidity and high yield do not coexist at Toyosu for 1LDK units. The 3LDK segment at Toyosu tells a different story: 151.8x GRM (7.9% yield) on 11 sales at ¥59.8 million. Unit type selection at the same station can shift your gross yield by more than 5 percentage points.
Monzen-nakacho, another well-known name in the Koto lifestyle circuit, produces a 553x GRM (2.2% yield) on 2LDK units at ¥100 million. Eight-year-old buildings, 9 minutes from the station. The brand commands a price the rent market does not validate.
The Demand Ratio Problem at Shinonome
Shinonome's yield number is genuine, but there is a data point investors should not skip. The supply-demand ratio at Shinonome is 0.79: 57 sales transactions versus 45 rent listings. That is one of the lowest demand ratios in the ward. By comparison, Kiba shows a ratio of 33.4 (2,972 rent listings against 89 sales), and Morishita is at 17.3.
What this means practically: Shinonome's rental pool is thin relative to supply. Properties here may sit vacant longer between tenants, and vacancy assumptions in any underwriting model should be conservative. The yield is real at the transaction price, but investor-friendly pricing alone does not guarantee frictionless rental management. For those evaluating Shinonome seriously, running a 10-15% vacancy assumption rather than the standard 5% changes the effective yield picture materially.
What the Price-Per-Sqm Data Shows
Walk distance to the station commands a meaningful premium in Koto, but the relationship is not linear. Properties within 5 minutes trade at ¥923,000 per sqm. The 5-10 minute band is actually the most expensive at ¥1,000,000 per sqm, suggesting that the highest-quality buildings in Koto cluster in the near-but-not-adjacent ring rather than immediately next to stations. Properties beyond 20 minutes drop to ¥454,000 per sqm.
Building age produces a steep discount curve. Stock under 10 years old trades at ¥1,173,000 per sqm. The 10-20 year bracket is ¥1,067,000. By 30-70 years, the median falls to ¥562,000 per sqm. This is the structural explanation for why Minami-sunamachi and Higashi-ojima's older buildings generate such high yields on paper: the market is applying a substantial age discount that the rental market has not applied to the same degree.
This age-versus-price dynamic is well documented across Tokyo, and Koto follows the city-wide pattern. For a deeper treatment of how distance to the station compounds with building age, the analysis in our [distance-to-station impact piece](/blog/impact-of-distance-to-station-on-grm-and-yield) runs the same framework across the full Tokyo dataset.
What a Good GRM Looks Like in This Context
The Koto ward median of 264.6x falls in the middle range for Tokyo's outer and eastern wards. Adachi, a structurally similar ward to the north, produces a median of 267.1x with isolated pockets down to 143x. Koto's top performers at 134-165x are comparable with Adachi's best segments, which suggests the eastern-waterfront discount is consistent rather than ward-specific.
For reference on where Koto sits relative to the broader Tokyo market, our [Tokyo-wide GRM benchmark analysis](/blog/grm-benchmarks-by-layout) breaks down typical GRM ranges by layout type across all 23 wards. A 2LDK at 134x in Koto is at the low end of the Tokyo range for that layout, which is another way of confirming that Shinonome is priced unusually for its geography.
The question investors should ask is not whether Koto is cheap relative to Shibuya. The question is whether the industrial waterfront segment of Koto is cheap relative to its own rental income, and whether that cheapness reflects a durable structural discount or a temporary pricing gap. Based on 9,668 transactions, the discount appears structural. Shinonome's low demand ratio suggests the rental pool is thinner than at established locations, which is the most plausible explanation for why the price has not been bid up.
FAQ
What is the average GRM in Koto Ward, Tokyo? The market median GRM is 264.6x monthly, equivalent to a gross yield of 4.54%. This figure covers 9,668 transactions across the ward. Individual station-layout combinations range from 134.6x (Shinonome 2LDK, 8.9% yield) to 657x (Kiyosumi-Shirakawa 1LDK, 1.8% yield).
Which station in Koto has the best yield for investors? Based on our transaction data, Shinonome (2LDK, 7 minutes on foot) produces the best documented yield at 134.6x GRM monthly and 8.9% gross yield. Minami-sunamachi (3LDK) is comparable at 135.1x. Both involve trade-offs: Shinonome has a thin rental pool, Minami-sunamachi has older building stock.
Why is Kiyosumi-Shirakawa so expensive relative to its rental income? Kiyosumi-Shirakawa has attracted significant lifestyle and international buyer interest, which has pushed purchase prices into a range that local rental demand has not matched. The result is a 657x GRM for 1LDK units, one of the weakest yield profiles in the ward. Buyer demand is real; investor returns are weak.
Is Toyosu a good investment for yield-focused buyers? Toyosu is the highest-volume station in Koto with 2,272 transactions, but yield depends heavily on unit type. 1LDK units show a GRM of 575x (2.1% yield). 3LDK units at the same station produce 151.8x (7.9% yield). The unit selection decision matters more than the station choice at Toyosu.
What is the median price in Koto Ward? The median transaction price is ¥63 million across 9,668 sales, on a median size of 70 sqm. By layout: 3LDK median is ¥68 million (4,122 transactions), 2LDK is ¥69 million (3,259 transactions), 1LDK is ¥52 million (1,062 transactions).