“A nice Japanese housewife is not expected to do volunteer work for strangers. ‘If she has time to help people she doesn’t even know,’ her relatives would grumble, ‘why doesn’t she do more to help her own kids study? Why doesn’t she run for an office in the P.T.A. at their school?’ Most middle-class Japanese people seem to think that poor people deserve to be poor- it’s their own fault or the fault of their families and relatives. Nobody should expect help from total strangers. As for conserving nature, that is the job of biologists. My friends have a hard time justifying their passion for gardening to their husbands and in-laws. If they were to spend their afternoons taking care of injured wildlife or clearing marshes of trash instead of cleaning their houses and preparing special meals for their children, their families would probably disown them”
Polite Lies by Kyoko Mori page 176.
The first explanation would also explain silliness like Chara- ben (kyara-ben, making packed lunches in the shapes and colours of cartoon characters). It could also explain the boom and bust of Eikaiwa (Japanese conversation schools). Perhaps for a while it was one of the few acceptable hobbies for women to have and they didn’t have to explain why they were doing it, and so they all rushed into it. Later there were more options of what to do with their time, and Eikaiwa actually became a bit of an embarrassment due to various scandals and so you could more easily avoid uncomfortable conversations by doing hot yoga or ikebana.