Hey, sorry I've been completely inactive here.
As for answering, you would need to first get the bad ending ( which I believe is compulsory before being able to get the 40k ending in the first place ), then once you finish the 40k ending thus unlocking metsu mode, unlock the 6 memoirs ( I don't really think there's a specified point cap for them, essentially hold space and you should have them after each failure but I might be wrong ) and then go ahead and aim for the 100k ending thus giving you the smiling irisu and jingle sound hinting at the game's story completion.
I hope this helped, if you have any other questions just ask here or if I don't get back @jubiieus on twitter.
If you need any extra help feel free to ask me too, though Kelnin's much better at Irisu Syndrome than me :^) either way good job with the 100k run and good luck with the 100% one if you choose to, I might try and upload one myself sometime soon :)
So basically I was gonna do a banned% run, but whenever i open the game in my browser it lags like hell, and my PC is fully able to run virtually any game, any ideas why?