I’m really excited to see the topics you will be bringing to the group!
Your background is ironic. What part of Japan is your family originally from? And do you know any other details on her conversion story that you are willing to share?
Daoism/Taoism is very fascinating. I find Julia Ching’s book Chinese Religions an easy read and helpful in better understanding basics of Daoism as it’s originally from China and later came to Japan.
In Japan, I believe it was largely implicitly impactful to the existing Shinto beliefs (and maybe a little for Buddhism), rather than an explicitly impactful as a separate religion. Japan has always been able to amalgamate things into their own. I’m not too keen if there are any specific sects of Daoism today in Japan, but I hear in China today it’s tied into a lot of ancestor worship and and general magic. (Maybe someone is more familiar with Daoism in China today.)
The basis of Daoism is “the way,” a philosophy of belief that everything is tied to nature in a mystical, spiritual way that eludes us, but we may be on it and not realize it. Sages provide insight and practice meditating on what the way is. There are a lot of interesting writings on “the way” because in essence you cannot fully comprehend the way, and if you think you do, you’ve missed it… Or something like that. Anyway, this way (we) and letting life be (wu-wei) is a philosophy that could be easily fit into existing Shinto practices and philosophy in Japan without needing to be separate. Perhaps the only iconic difference would be if someone held to any specific deities of the many that are a part of Doaism. Again, not unlike general Shintoism that worships any number of deities at any time, sometimes bound by a specific region, mountain, river, tree, etc.
Daoism has supposedly held a belief in three key elements, but this seems to take more shape in later years, likely under the influence of Christianity. There is this trinitarian idea of a Highest One, the Precious One and a “Power-of-the-Way” One. I’ve not performed extensive research on this, but I personally would not make too much of it other than borrowing ideas from Christianity (though admittedly this is just my hunch).