It's been quite some time since my last post, but I wanted to tell you that I'm working on a spreadsheet for every Yo-Kai's chances of being befriended from the first game, since it seems like it doesn't exist on the internet.
Obviously you must know that the chances I'm writing are not the real ones from the code, but actually the results I get after experimenting, soft resetting, and trying stuff, so if you try you might not have the same results, but if you want you might be able to share the info to update the spreadsheet in the future. Also, you must also know that percentages are actually statistics, and if you don't know, statistics only tell how often something might occur, but it still is random. In summary, if it says that something has a 50% chance of occuring that doesn't mean that you can't have the same result 7 times in a row just because it's 1/2.
And finally, I'm only able to work on this because I'm on holidays, so it will take time, understand that I need to test multiple (I really mean a lot of) times hundreds of Yo-Kais just to make the chances more precise, and since a lot of Yo-Kai are actually really rare, it takes a lot of time just to get info.