RetireJapan

I have been working as a sole trader for a few years but my accounts are basically non-existent. I tried using freee a few years ago but I didn't really understand it. Right now I don't really have a good idea about how much money is going out and coming in every month. I'd like to have some kind of overview of this but I don't really know where to start.

Can anyone recommend some basic books/tutorials for business bookkeeping, in general and for in Japan.

If you are working as a sole trader, I think it is important that you have indeed an idea of your numbers!
You can find many tutorials on Youtube to help you understand the basics. Depending on your level of Japanese, I recommend you start with books or tutorials on Boki level 3.

You can also use the following free excel template which will generate your balance sheet and profit and loss statement quite easily. http://management.main.jp/excelb.html