May 7, 2026
By the HalfKey team
Tokyo apartment internet without a 2-year contract
Most foreigner guides assume you sign a 24-month NTT or NURO contract and wait 3 to 8 weeks for installation. On a 90-day stay, none of that fits. Three other paths exist; the speeds, lock-in, and failure modes are different for each.
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The standard advice in Tokyo Cheapo, Plaza Homes, and apts.jp is to sign フレッツ光 (Furettsu Hikari — NTT's residential fiber service) or NURO 光 (Nūro Hikari — Sony's faster fiber line on its own backbone). The contract runs 24 months. The technician arrives in 3 to 8 weeks. You pay a cancellation fee if you leave early. That advice is correct for a 2-year resident. It is wrong for a 90-day midterm tenant.
For a midterm guest, the contract is the lever. A 24-month line on a 3-month stay means a ¥10,000 to ¥25,000 early-termination fee. Add the ¥3,300 install cost. The technician arrives in week 4. You move out in week 12. The math does not work.
Three midterm-friendly paths exist instead. Each one trades speed, latency, or data cap for the absence of lock-in. Pick by what your work needs, not by what looks fastest on the brochure.
Three levels: city, ward, building
City level is what the carrier networks support. Tokyo has continuous 5G coverage from KDDI, NTT Docomo, and SoftBank across all 23 wards. The fiber backbones reach every residential block inside the Yamanote line and most of the outer wards. Coverage is not the constraint. The contract is.
Ward level is where the speeds vary. Pocket Wi-Fi on the SoftBank network in central Setagaya hits 80 to 150 Mbps download in 2026 testing. The same device in western Suginami around Eifukucho drops to 25 to 60 Mbps at 6pm. eSIM speeds on the Docomo network track the same curve. Faster in central wards, slower in the residential rim. Check the carrier's coverage map for your ward before you commit.
Building level is the largest variable. About 60 percent of post-2015 manshon (mid-rise concrete apartment) come with 全戸一括 (zenko ikkatsu — "all-units bulk," building-wide internet contracted by the building owner and shared across every unit) already wired in. The internet is in the wall. There is no contract, no installation, no router setup beyond plugging into the wall jack. Older buildings and most low-rise アパート (apāto — wood-frame apartment) do not have it.
Check whether your unit has zenko ikkatsu before reading further. The operator's listing usually says インターネット無料 (intānetto muryō — "free internet") in the amenities row. If the listing says 光配線方式 (hikari haisen hōshiki — "fiber wiring method") under the equipment section, the wall jack is wired but you must contract a provider. Those are not the same thing.
Path one: building-included internet
The cleanest midterm path is the one already in the apartment. zenko ikkatsu uses one master fiber line shared across every unit in the building. The building owner pays the carrier ¥250 to ¥600 per unit per month. The tenant pays nothing extra. The operator builds it into rent.
The wall jack is usually labelled LAN or インターネット and sits behind the TV. Plug an Ethernet cable into your laptop or into a router you brought. The connection is live. No router credentials, no PPPoE setup, no carrier login.
Speed is the catch. zenko ikkatsu lines max out at 100 Mbps to 1 Gbps shared across the building. A 60-unit manshon on a 1 Gbps line at peak load 7pm to 11pm delivers 30 to 80 Mbps to your unit. Ping to a Tokyo data center sits between 8 and 25ms. Fine for video calls, fine for streaming 4K, fine for cloud-IDE remote development. Not fine if you upload large files daily or run a multi-camera live stream.
A second catch is the building's IP routing. Some zenko ikkatsu setups put every tenant behind the same NAT. That breaks port-forwarding tools (Plex, self-hosted homelab, certain VPN configurations). It also trips fraud-detection on banking apps that flag the shared IP. If your work needs port-forwarding, this path fails.
Test before you trust. Run fast.com on the wall jack within an hour of move-in. If you see 60 Mbps or more at off-peak times, the building line is fine. If you see under 20 Mbps at 9am, the master line is oversubscribed. Plan for a backup path.
Path two: pocket Wi-Fi rental
If the building has no zenko ikkatsu and your stay is under 6 months, a pocket Wi-Fi rental is the next-cheapest path. Sakura Mobile, CDJapan Rental, and a handful of inbound-focused JP services rent the device on rolling monthly contracts. No long-term lock-in.
Sakura Mobile in 2026: 100 GB per month at ¥5,478, 200 GB at ¥7,128, ¥5,000 activation fee, cancel any month after the first. The device runs on the SoftBank network. Download speeds peak at 187 Mbps under good conditions. 60 to 100 Mbps is typical in central Tokyo at peak hours. Battery is rated 20 hours; in practice 10 to 14 with active use.
CDJapan Rental's WiMAX 5G plan: ¥6,400 to ¥7,900 per month depending on commitment length, unlimited data, ¥0 cancellation fee on the rolling tier. WiMAX runs on the KDDI / au backbone. Theoretical peak is 1 Gbps; rarely seen in practice. Real-world speed in central Tokyo is 100 to 300 Mbps. The throttling clause says heavy users may be slowed. In practice it is not triggered for full-time WFH usage of 50 to 100 GB per month.
Two failure modes to plan around. First, latency. Pocket Wi-Fi adds 30 to 60ms of jitter compared to fiber. Real-time games and ultra-low-latency voice (some VoIP softphones) feel laggy. Standard Zoom, Google Meet, and Teams calls work fine. Second, the device is small. A WiMAX router on a kitchen counter pulls 30 percent slower in a back bedroom than at the window. Concrete walls absorb the signal. Run a speed test from where you actually work, not from where the device charges.
Two services to avoid for a midterm stay. The airport-counter daily-rental kiosks (the ones marketed at tourists) charge ¥800 per day and ¥24,000 per month. That is more than double the JP-resident rate. The cheap "100 yen" trial pocket Wi-Fi plans almost always have a 24-month auto-renew clause hidden in the smallprint. Read the renewal section before you sign.
Path three: eSIM unlimited data
The newest path, and the one Plaza Homes does not mention at all, is an eSIM with an unlimited or near-unlimited monthly plan. You install a QR code on a phone or a 5G-capable mobile router. There is no physical SIM, no installation visit, no device rental. Activation takes 10 minutes.
Mobal in 2026: ¥990 per month for a Japanese-number eSIM with reliable Docomo coverage, billed on the 1st, no contract. Data over 500 MB is charged separately. For full-time WFH, the higher tiers run 30 GB per month at ¥2,500 to ¥3,500. Mobal's 5G unlimited eSIM (3 to 31 day terms) operates on the au network. It is the closest thing to a no-cap option for a stay under one month.
Sim Local, Holafly, and Airalo sell unlimited-data eSIMs marketed at travelers. The pricing is monthly, the speeds are 4G/5G. Most caps trigger only after 100 to 200 GB per month or 10 to 20 GB per day. These are not Japanese-number plans. You get data only, no voice line, no Japanese SMS reception. If your work needs OTPs to a Japanese number (some banks, some employer SSO), the eSIM-only path fails on that requirement.
Two failure modes. First, hotspot caps. Some carrier eSIM plans cap tethered usage at 5 to 30 GB even when the headline plan is unlimited. If you tether your laptop off the phone, you hit the cap fast. Read the hotspot section of the plan, not the headline.
Second, fair-use throttling. "Unlimited" in Japan typically means 1 Mbps after a soft cap. WiMAX throttles after 10 to 30 GB in three days. Some eSIM plans throttle after 50 to 200 GB per month. 1 Mbps is enough for email and audio calls. Not enough for HD video calls. If your work is 4 hours of Zoom a day, you will hit the cap by week three.
When each path fails
The three paths are not interchangeable. Each one fails differently.
Building-included fails when the master line is oversubscribed (30 Mbps at 9pm in a 60-unit tower). It also fails when the building NAT breaks your tool. Test inside the first 24 hours. If it fails, switch to path two or three the same week.
Pocket Wi-Fi fails when you need a wired Ethernet connection (some employer VPNs require it). It fails when latency matters (real-time gaming, ultra-low-latency voice). It fails when you work from a back room with thick concrete walls. Run the speed test from the work spot before you sign a second month.
eSIM fails when you need a Japanese phone number for SMS OTP. It fails when you need wired Ethernet. It fails when you need more than the throttled-after-cap data budget. It also fails on the cheaper plans when hotspot tethering is capped at 5 GB per month.
The cleanest setup for a 90-day full-time WFH stay is zenko ikkatsu plus an eSIM as backup. The building line carries video calls. The eSIM covers the days the master line goes down. Total monthly cost: ¥0 plus ¥990. That is ¥7,000 a month and four weeks of install wait ahead of the standard advice.
Reading the listing before you book
The operator's listing tells you which path is available. Read it before you book.
If the amenities row says インターネット無料 or "free internet" with a speed in Mbps, the unit has zenko ikkatsu. The speed shown is the building's master-line capacity, not your delivered speed. Halve it for peak-hour estimation.
If the amenities row says インターネット有料 (intānetto yūryō — "internet at extra cost"), the building has a wired connection but the operator passes the per-unit cost. A monthly fee shows on top of rent. Common in older serviced apartments. Confirm the speed and the contract terms before you book.
If the listing says 要相談 (yō sōdan — "negotiate") or omits internet entirely, assume there is no zenko ikkatsu. Plan for path two or three. The filter at listings.halfkey.jp for stays under 90 days surfaces buildings that disclose internet status in the amenities row.
If the listing mentions ホームルーター (hōmu rūtā — "home router," a 5G-router unit the operator has placed in the unit), that is path two pre-installed. The operator usually rents the device on the same cycle as the unit. Ask whether the data is unlimited or capped before move-in. Some operators install a 100-GB plan and the cap hits in week two of full-time WFH.
Before the first day of work
Run fast.com from the wall jack within the first hour of move-in. Note down speed, up speed, and ping. Save the screenshot. If the building line is under 20 Mbps at off-peak time, message the operator the same day. Some buildings have a switch in the entryway closet that resets the master router.
Order the eSIM the day before you fly. Mobal and Sim Local deliver the QR code by email within 30 minutes of payment. Activate the eSIM after you land at Haneda or Narita on the airport Wi-Fi. The eSIM is your backup if path one fails on day one.
If the building has no zenko ikkatsu and you need wired internet for work, sign a Sakura Mobile or CDJapan rolling plan. Pick the 200 GB or unlimited tier, not the 100 GB tier. Full-time WFH burns 80 to 120 GB a month even without video. Add the cushion.
Skip the 24-month NTT contract regardless of what the relocation forums recommend. The midterm guest does not need it. The cancellation fee plus the 4-week wait is the cost of taking that advice without checking your stay length.
If the operator pre-installed a hōmu rūtā with a capped data plan, ask before you arrive whether the cap can be raised. Most operators will swap the SIM for a higher-tier plan and bill the difference. The upgrade is cheaper than buying a parallel pocket Wi-Fi.
— halfkey lists midterm furnished apartments with internet status in the amenities row. Filter at listings.halfkey.jp to confirm zenko ikkatsu before booking.