What code should I add to send a text message with a Japanese mobile phone number?

Hello! I have a friend in Japan. It started with text messages. If you send it to him, you need to add +8 1 before his Japanese mobile phone number. 8 1 is the international code of Japanese communication, and China's is 86, so when someone sends a text message, our mobile phone will display +86 * * * … like this. But remind you, texting is very expensive! One yuan each. There are various packages in Japan, some of which are monthly. Sending messages to China is free! There are many calling cards, and making international calls is not as expensive as we thought! Haha's laughter ...