She preaches the gospel of her KonMari Method of organization, and I do think her basic tenets are good ones: be mindful of the things you have and don't keep things if they don't bring you joy. It's certainly easier said than done, though she is very insistent that this process is easy and fool-proof.
Her method involves a one-time (though that "one-time" can take up to 6 months) major purge of everything you have and really considering what do you need and what makes you happy. She claims after this purge, she's NEVER had a person revert to their old ways and that once you do this you will be happier, less stressed, lose weight, get clear skin, find the love of your life, probably win the lottery, etc*.
Most of the book focuses on the importance of getting rid of things. An empty room seems to be the ideal. She provides a few tips for being organized, some I liked (fold your clothes and place them vertical in your drawer so you can see everything, organizing by category instead of room so you know what you actually have), many I won't be doing (never keep anything in your tub/shower, dry your dishes on your veranda and you won't need a drying rack [you have a veranda off your kitchen, right?], move your bookshelf into a closet).
There are some exceptions to the "bring you joy" bit, as she does grudgingly admit that paperwork isn't likely to bring you joy but sometimes you do need to hold onto important things like warranties or tax forms. HOWEVER, she is adamant that the second you can throw these things out that you do. Immediately. Have you paid your credit card bill? Excellent THEN TRASH IT IMMEDIATELY. No, don't think you can organize paperwork. It's a losing proposition.
She talks about her own history with organization and tidying up, starting when she was 5 and no matter what she claims or the testimonials she provides, I do not believe you will ever be as orgasmically happy as she is when she's tidying.
She anthropomorphises things, talking about how you shouldn't ball up your socks because they have worked hard when they're on your feet and their time in the drawer is when they should be relaxing and they can't relax when they're squished up like that. And I kept thinking how it's hard enough to throw things out without believing they have feelings. (I blame The Brave Little Toaster for this.) Though she does address this problem of throwing away something with feelings by saying that if something is balled up in the back of your closet or whatnot and never used, it's basically in prison so you should set it free. She does not go into what that new freedom might be like for your old knickknacks if tossed into an incinerator at the dump.
Her tips also aren't great for people on a budget. She doesn't recommend stocking up on items to save money because she says you spend more money storing them and if you throw out something and discover you need it later, just buy it then! There's also an assumption it's very easy for you to run out and pick up whatever it is you need, so there's never the need to keep things on hand. I can't see this book being a bestseller among the couponing crowd.
I won't be taking on the KonMari Method, but I like the idea of going through our items and discarding what we really don't need, what we won't miss. There are going to be things we keep that don't necessarily bring me joy (sorry, packing tape, you're very useful and I'm keeping you around, but my heart doesn't soar when I see you) and I'm not going to start thanking all of my possessions for what they've done for me each day, but I think there are some good lessons to be taken away from this book.
Title quote from page 21
Kondo, Marie. The Life-Changing Magic of Tidying Up: The Japanese Art of Decluttering and Organizing. Ten Speed Press, 2014