being connected where-ever you are and go, is necessary in business as well as for pleasure . but our Planet Earth is still divided in differing countries, with some using incompatible frequencies . while traveling abroad : voice-calls can be received and made via roaming from your local phone, data transfers which includes SMS messaging as well as internet connection can be unstable AND costly depending upon your current carrier and subscription .

you have more alternative choices if using a smart-phone or iPhone : to use pre-paid SiM Cards . the caveat here is that many developed countries including Japan requires residency to sign-up for voice-call plans, so you are left with SiM Cards that can make only data connections for maps and internet browsing, except SMS messages . thus all here are just for internet ONLY, however I will note when one can use messaging also . further-more I should note listed speeds are for reference only, as they come-and-go depending upon city and location, and more importance should be put on stability and valid date limitations, which I will describe here mostly .


NTT Docomo PrePaid SiM 7-day Y2900 or 14-day Y3500 versions
– 100MB per Day at listed maximum 262.5Mbps
– after above allotment is used : 200kbps

some common factors on three products introduced below, among about half-a-dozen currently used in Japan :

  • all are 1GB capacity useable for a Month, where 2GB can be used longer,
  • all can be recharged (until 14 Days after cut-off) and usage extended through their website .

▶(photo below) Sony So-net PrePaid LTE SiM 1GB 30days Y3,000
picky restrictions : as you have to register at their website within 14 days from purchase, or expiration date (roughly 6 Months from when they put it on sale) which-ever comes first . then it is valid for 30 Days there-after, so should purchase this imminent to actual use . 2.2GB version can be used for 30 Days also while 3GB capacity : 60 Days . using NTT Docomo network with maximum download speed listed as 225Mbps . Japanese, Korean, Chinese, Thai and English manual with Support 10am~5pm in either Japanese 0120-217-260 and English 0120-688-260 .
▶(above photo, center) WireLess Gate Yodobashi Camera PrePaid Sim 1GB+WiFi Y2,650
– uses NTT Docomo 4G LTE, 3G cellular and WireLess Gate WiFi HotSpot signals
– expiration about 3 Months after purchase, and usable for 14 Days after activation (2GB version is 30 Days and 3GB : 60 Days).
– noted maximum download speed 150Mbps, and upload 50Mbps
– manual in Japanese, Korean, Chinese and English
– English Support 10am~6pm

▶(above photo, bottom) iiJmio Japan Travel SiM 1GB+Wi-Fi Y2,650
expiration date approximately 6 Month from sale, and service period 30 days there-after, using NTT Docomo network with listed maximum upload 225Mbps and download 50Mbps . 2GB version can be used for 3 Months . manual in Japanese, Korean, Chinese, Thai and English Support (Japanese, Chinese and English) 9am~7pm Tel.03-5205-4999


a couple of On-Line sellers in South Korea provides the first pre-paid SiM Card listed above, along with others for use in neighboring Japan, Taiwan, Hong Kong, China and the States – among which one can arrange for pick-up at inCheon Airport . then in Japan : most can be had at larger airports and train stations . if you cannot find a vendor : it will be a vending machine as much drinks are . other than that you will have options at electronics discount outlets : among which the largest Yodobashi Camera has about half-a-dozen choices, while its competitor Big Camera only has a single product line .

most SiM Cards would set itself up automatically, but sometimes don’t and it really is a matter of which type and maker you end up with, on which phone – all of which change so not worth mentioning here thus will NOT reply to inquiries on specific models . that is why there are detailed instructions on all above, although in tiny text in Japanese as well as English plus more Asian languages .

– Korea Tech BLog –