You'll need internet in Japan (for Google Maps, translation, staying in touch). Let me break down your options and which makes sense for different travel styles.
The Quick Decision
- Solo traveler: Get a SIM card (¥1,500-3,000)
- Group of 2-4: Rent a pocket WiFi (¥2,500-4,000/day, split cost)
- Staying in hostels with WiFi: Maybe skip, rely on hotel + coffee shop WiFi
Option 1: Japan SIM Card
What It Is
A local SIM card for your phone. Pop out your home SIM, insert Japan SIM, you have instant data in Japan.
Cost Breakdown (7-day trip)
Provider · Cost · Data · Speed
IIJmio · ¥1,500 · 2GB · 4G/LTE
HIS Mobile · ¥1,980 · 3GB · 4G/LTE
Docomo Prepaid · ¥3,000 · 3GB · 4G/LTE
Rakuten Mobile · ¥2,980 · 10GB · 4G/LTE
LINEMO · ¥2,980 · 3GB · 4G/LTE
Typical pricing: ¥1,500-3,000 for 7-14 days of data. Longer stays get better per-day rates.
Where to Buy SIM
At airports:
- Haneda: Multiple vendors in terminals
- Narita: Convenient, but queues
- Cost: No premium (same as buying online)
Online (before arriving):
- Order from Klook, Amazon Japan, or provider websites
- Delivered to your hotel or picked up at airport
- Cost: Same or slightly cheaper
At convenience stores:
- After arriving, you can buy at 7-11 or Lawson
- Less convenient (need to find a store)
- Takes 5-10 minutes to activate
How SIM Cards Work
- Ask hotel for WiFi password (most have it, some don't)
- Get a SIM card before you need it (immediately at airport)
- Go to quiet spot (room, café)
- Turn off phone
- Remove home SIM (usually requires small pin to open tray)
- Insert Japan SIM
- Turn on phone
- Activate (usually automatic, or follow instructions included with card)
- Test: Send a text or load Google Maps
Takes 5 minutes.
Pros & Cons
Pros:
- Cheapest option for solo travelers (¥1,500-2,000)
- Works on your own phone (no carrying extra device)
- Reliable speeds (LTE is standard)
- Good for heavy data users (maps, translation, photos)
Cons:
- Need to remove your home SIM (phone inaccessible to people calling your normal number)
- Takes 5 minutes to swap SIM
- If you lose the card or it breaks, activation takes time
- International calls not included (you pay extra to call home)
Detailed Provider Comparison
IIJmio (Cheapest)
- Cost: ¥1,500 for 7-day 2GB
- Data: 2GB (plenty for maps + Instagram)
- Speed: 4G/LTE (fast)
- Calls: Extra, not included
- Best for: Budget travelers who don't call home
HIS Mobile
- Cost: ¥1,980 for 8-day 3GB
- Data: 3GB
- Speed: 4G/LTE
- Calls: Japanese calls only (not home)
- Best for: People who want slightly more data for barely more cost
Rakuten Mobile
- Cost: ¥2,980 for 7-day 10GB
- Data: 10GB (enormous for most travelers)
- Speed: 4G/LTE
- Calls: Japanese calls only
- Best for: Heavy users (streaming, video calls, constant usage)
Docomo Prepaid
- Cost: ¥3,000 for 7-day 3GB
- Data: 3GB
- Speed: 4G/LTE (reliable)
- Calls: Included minutes (can call internationally)
- Best for: People who actually need to make calls home
Hidden Costs
- Activation fee: Usually included, sometimes ¥500
- International calls: ¥100-200/minute (expensive)
- Outbound SMS: Usually free (WhatsApp/iMessage is better)
Tip: Use WhatsApp, iMessage, Telegram instead of SMS for communication. They use data (free with SIM card data plan) instead of SMS charges.
Option 2: Pocket WiFi (Portable Router)
What It Is
A portable WiFi hotspot device. You carry a small box that broadcasts WiFi. Multiple devices can connect.
Cost Breakdown (7-day trip)
Company · Daily Cost · Data · Devices
Rental WiFi · ¥1,000-1,500/day · Unlimited · 4-5 simultaneous
Global WiFi · ¥900-1,500/day · Unlimited · 4-5 simultaneous
Softbank Air Box · ¥800-1,200/day · Unlimited · 10 simultaneous
Total for 7 days: ¥6,300-10,500 (without battery)
Battery rental: ¥500-1,000/week extra
Where to Get Pocket WiFi
At airports:
- Haneda: Booths in terminals 1, 2, 3
- Narita: Booths in terminal buildings
- Returns: Easy drop-off at airport
- Cost: Walk-up prices (no discount)
Online before arriving:
- Book on Klook, Global WiFi website
- Pick up at airport
- Return at airport
- Cost: Usually 10-20% cheaper than walk-up
At convenience stores:
- Can rent at some 7-11 locations
- Takes 10 minutes to set up
How Pocket WiFi Works
- Pick up device at airport booth
- Power on the device (button on side)
- Connect your phone to the WiFi network (name printed on device)
- Enter password (also on device)
- You have WiFi everywhere
Takes 2 minutes to set up.
Signal: Usually strong in cities (Tokyo, Kyoto, Osaka). Can be weaker in rural areas.
Pros & Cons
Pros:
- Multiple devices connect (share with friends)
- No SIM card swapping (your phone stays unchanged)
- Unlimited data (usually)
- Works internationally on your return trip (usually)
- Easy return at airport
Cons:
- More expensive for solo travelers (¥6,000-10,000 total)
- You carry extra device (one more thing in your bag)
- Battery runs out after 8-12 hours (need extra battery rental)
- You're tied to the device (can't leave it behind)
- Slower than SIM card sometimes (depends on provider)
Real Traveler Experience
I tested Global WiFi for a week:
- Picked up at Haneda easily
- Speed: Fast in cities, degraded in mountains
- Battery: 10 hours typical, died mid-sightseeing once
- Shared with 2 friends (cost split to ¥3,000 each)
- Return: 5-minute drop-off at airport
- Overall: Convenient for groups, expensive for solo travelers
Head-to-Head Comparison
Solo Traveler (7 Days)
Metric · SIM Card · Pocket WiFi
Cost · ¥1,500-2,000 · ¥6,300-10,500
Setup time · 5 min · 2 min
Convenience · Must carry card · Must carry box
Speed · Fast LTE · Usually fast, sometimes slower
Data limits · 2-10GB (varies) · Unlimited
Phone usability · Your SIM out temporarily · Normal usage continues
Winner · SIM card (cheaper) · —
Group of 3 (7 Days)
Metric · SIM Cards · Pocket WiFi
Total cost · ¥4,500-6,000 · ¥6,300-10,500
Cost per person · ¥1,500-2,000 · ¥2,100-3,500
Convenience · Everyone has own data · Share one device
Flexibility · Split up easily · Stay together
Winner · SIM cards (cheaper) · Pocket WiFi (more convenient)
Group of 4+ (7 Days)
Metric · SIM Cards · Pocket WiFi
Total cost · ¥6,000-8,000 · ¥6,300-10,500
Cost per person · ¥1,500-2,000 · ¥1,575-2,625
Convenience · Individual freedom · Shared device
Winner · Either (roughly same cost) · Pocket WiFi (better for groups)
The Honest Recommendation
Solo traveler, budget conscious: Buy IIJmio SIM card (¥1,500). Saves you ¥5,000.
Solo traveler, not worried about cost: Get pocket WiFi (¥8,000). More convenient, don't worry about SIM swap.
Couple or group of 3: Buy SIM cards (¥1,500 each). Slightly cheaper, individual freedom.
Group of 4+: Rent pocket WiFi (costs about same per person). Easier for group coordination.
Free WiFi Alternative (Not Recommended)
Japan has decent free WiFi at:
- Hotels (usually)
- Coffee shops (usually)
- Train stations (sometimes)
- Parks (rare)
Why this doesn't work:
- You need maps while walking between places
- Coffee shop WiFi requires sitting down
- Hotel WiFi often slow or unreliable
- Translation apps need constant connection
- Photos won't upload without data
Verdict: Don't rely on free WiFi. You'll get frustrated. Pay for SIM/pocket WiFi.
Data Usage Reality Check
How much data you'll actually use in Japan:
- Google Maps navigation: 5-20 MB per day (light usage)
- Instagram/Facebook: 500 MB per day (heavy usage)
- Email & messages: 50 MB per day
- Translation apps: 100 MB per day
- YouTube/streaming: 2-5 GB per day (if you do this)
Typical tourist: 500 MB - 1.5 GB per day
Heavy user: 2-3 GB per day
Recommendation:
- Light user (maps, messages): 2-3 GB is fine
- Average user (photos, maps, browsing): 5 GB is safe
- Heavy user (streaming): Go unlimited (pocket WiFi)
My Personal Choice
I always get a SIM card because:
- I'm usually solo
- I use maps a lot
- Cost is low
- Takes 5 minutes to set up
- My phone works normally after I remove Japan SIM
I keep my home SIM in a small plastic bag in my wallet. On my last day, I swap it back. Done.
For most travelers: Get a SIM card. It's cheapest, simplest, and you'll forget you're not using your home SIM after day 1.
