A pocket Wi-Fi is a battery you pick up and return. An eSIM is a plan on the phone. For a backpack and one phone, the eSIM is usually simpler.

Copied 29 Aug 2026 from official Japan pages (not blogs):

• Airalo Japan 7-day 5GB $10. Unlimited 7-day $27 (3GB/24h then 1 Mbps). SoftBank +1.
• Ubigi 10GB/7 days $14 on Docomo. The 7-day unlimited SKU some posts still quote was 404.
• Holafly Japan 7-day $27.50. Hotspot 1GB/day.

Suica tap is FeliCa, not eSIM. Most overseas Android phones cannot add Welcome Suica Mobile. IC tap can work with no data. Maps and top-up still need a line. Install on hostel Wi-Fi the night before, not in the NRT/KIX corridor.

Dated notes: https://before-you-land.tiiny.site/japan/pocket-wifi/

Disclosure: Airalo URL is Travelpayouts affiliate. Holafly and Ubigi stay official. https://tp.media/r?campaign_id=541&marker=771402&p=8310&rs=567948&u=https%3A%2F%2Fwww.airalo.com%2Fjapan-esim