Note: The run has changed drastically since this guide was written. All current guides are in Japanese.
The guide was written for hard mode, but they can be used in normal/easy mode or a mixed difficulty run. Easy/Normal mode gives less exp, so you may need a few extra levels or skill levels to guarantee the RP needed to craft the sword before Meline.
This is for the most recent run that uses a lot of glitches to fly really fast, skip a ton of fights, and skip a few cutscenes as well. The run works on v1.0.0 for PC, or v1.0.2 on non-JP Switch. If you're on PC and the devs decide to fix the game, you can likely downpatch with Depot Downloader and replace the files to run this.
https://docs.google.com/document/d/1g_z6NF3jwtknDmQGUXUC1wHpMaVOnKuizhkXkujejjE/edit
These are shorthand notes in calendar form. I colored stuff in red to remind myself of things I forget a lot. Feel free to make a copy to get rid of the colors.