I wrote a short guide titled “Minimal Guide to Learning Japanese” – originally just for some friends who were interested – to explain how I would recommend learning Japanese from scratch. I never intended to share this guide here but figured that I might as well. The design goals are (in order) speed, simplicity, and trustworthiness: (1) the primary goal is to learn as fast as possible; (2) simple and 95% optimal is better than complex and 99% optimal; (3) the method should obviously work (i.e. omit any strategies without extensive empirical evidence).
This guide does not recommend any textbooks. This is not because I have any personal vendetta against textbooks. I self-studied Genki and Tobira and am personally inclined to prefer textbooks. I just found that it was possible to cover the same ground faster without them.
This guide is only concerned with time cost, not monetary cost. The original target audience of this guide was friends who happen to be relatively well off. That doesn’t mean all of the recommendations are expensive, only that monetary cost was never a consideration.
The guide recommends Torii SRS. My personal preference is a highly customized Anki deck with Yomichan integration and several plug-ins, although I opted for a “batteries included” solution that is 90% as good for the purposes of this guide. Wanikani is solid also. I don’t have strong opinions on the particular SRS application.
Feel free to share what you would change.