I was in Japan for a month and a half in February and March and stayed in different hostels or capsule hotels, every 2-3 days all over Japan. Most instances of people being rude in my experience involved other Asians. In one capsule hotel I stayed at, I woke up to a Japanese guy in a capsule across from mine having a phone conversation at 3 am. I heard another Japanese guy beg him to stfu but he just kept going but in a lower voice. In another hostel, a Filipino guy was in his bed on his phone talking and laughing at like 4 am.

Germans and Australians were by far the friendliest foreigners I met in Japan. Loudest were Italians. Americans/Canadians were invisible because I don't remember meeting or seeing any of them.