Normally, smartphones can be conveniently used in various situations, but they are even more valuable when going abroad. You can check your current location and route on a map, keep in touch with family and friends in Japan on SNS, and enjoy communication with local people using a translation app.
There are several ways to use your smartphone abroad. For example, the method most people currently use is to rent a mobile Wi-Fi router for overseas. You don't have to make any changes to your smartphone, and you can easily use it by connecting via Wi-Fi. The charge varies depending on the destination, but it can be used for around 1000 yen per day, and it can be used by multiple users, so rent one mobile Wi-Fi router for a trip with a friend. You can also use it like this.
However, when renting a mobile Wi-Fi router for overseas, the departure date and return date are counted in the number of days, and because it is a rental, compensation costs etc. are incurred, so it exceeds 10,000 yen for a trip of about one week. It is not uncommon for them to end up.
Another method is to purchase a prepaid SIM locally, which is often written by writers, including myself, in this magazine's "Minna no Keitai". Prices vary depending on the destination, but in general they are available at the same or slightly cheaper rates as we normally use in Japan.
For example, when I bought it at Mobile World Congress 2018 in Barcelona, Spain, a package of 4.5GB for 10 euros (about 1350 yen) and 6GB for 20 euros (about 2700 yen) was sold. However, in the case of prepaid SIM, you can not purchase it unless you search for a store that sells it and explain it in English or local language, and you also need to know the charge system of the prepaid SIM of the mobile phone company to some extent. The hurdle is a little high. If it is sold at an airport, you can buy it immediately, but it is not uncommon for you to go out into the city, search for shops of each mobile phone company, and run around for inventory.
At the same time, it is necessary to prepare a smartphone that unlocks the SIM lock, and it is also necessary to consider the compatible band of the mobile phone company at the destination, so it is hard to say that it can be easily used by many people.