Maybe 1/2 of Japanese kids commute 1 hour or more on the train every day, alone.
IT'S NORMAL.
My three daughters lived with us in Japan 1988-2002. The youngest one was born there. We lived in the Tokyo area 1988-1994 and the Kobe area after that.
One summer, the two youngest wanted to go visit friends in Tokyo, who had invited them to spend a week.
They begged until we relented and rode local trains all the way there and back, roughly 6 hours each way. In those days, the trains offered a set of five or six all day tickets for around 10,000 yen. They were good only during the vacation season and on the local trains since the local trains ran under capacity and the express/Shinkansen were more crowded than normal.
What's more, they met other kids on the train doing the same thing. We used to have a country where kids could so that too.