This mod is probably only helpful if you're playing OT for the first time like me. While I understand the guide myself, please point out if you notice any inconsistencies, errors or parts that can be better formatted. I did simplify some parts so for those you can use the Steam guide if you don't get it.

You can open up the guide by visiting the tavern and selecting "Hear a Tale" or by entering the relevant town. The guide is appended to the end of the chapter description. Every traveler is abbreviated to two letters, the | sign indicates a boss or dungeon or some specific interaction where you need to bring someone in with you. There's a bit more nuance than that but I can't fit all of it within the margins of the GUI without looking cluttered. I gave an example below.

(Tr, Cy -> Ha -> Pr, Al -> Op -> Ol | ) indicates you can trigger Tressa and Cyrus at about the same time near or at the beginning, then switch to H'aanit, then Primrose and Alfyn, then Ophilia, then you need to take Olberic into the dungeon or boss fight, whichever triggers the banter. If it were ( ... -> | Ol) instead, that implies you have banter with Olberic after the boss fight / dungeon.

Better Descriptions included in the mod. (but not Side Story Helper because I don't use it)
I don't have a version of the mod that doesn't have Better Descriptions (everyone who uses mods uses it anyways), though if enough people want it i will make it

Compatibility: modifies the GameTextEN file so it's not compatible with Side Story Helper or other mods that uses that
Installation: Extract the file into Octopath_Traveler/Content/Paks
Mirror: https://files.catbox.moe/mjfwgr.7z