Can I send short messages on my mobile phone when traveling to Japan?

No, I wanted to buy a temporary Japanese phone card when I went, but the tour guide said I couldn't buy it when I arrived. You can start international roaming so that you can make phone calls and send messages. I bought a b-mobile wireless network card in Douban before I went there. Generally, there is no limit to the flow of a card. The first card is opened, and then the last card is bought one by one until the network card expires or I go directly to Taobao to buy a b-mobil. E's network card is also ok, a little more expensive. With this network card installed in the mobile phone, the mobile phone can send messages normally except for making phone calls, qq and surfing the Internet.