We first see the MM note during the second reset. We don't know for sure that it wasn't there before that, because we never see the board, but it would be odd if it was there before the first reset, since it would be meaningless/confusing to Sensei.
I have a strange proposition about this but I'll make a detour to an age-old question of mine first: when exactly did Maya leave her girl intro journal in Sensei's room?
If a reset "prior to the starting of the game" kills a previous Sensei iteration and places Maya also at Thursday afternoon, the exact same time when our Sensei wakes up 10 min after the class ended, how does she find the time to craft the journal, place it in Sensei's room, come back to the bistro for a suspiciously coincidental meetup with the new Sensei? How did she manage to do all that within the short timespan between
Every Day I Grow Some More and
A New You?
I would
probably give a pass to the assumption where Maya just does all these works
very very quickly as soon as a new cycle starts, and she does all that just in time so that a new and oblivious Sensei can have a guide to read on day one. Imagining this amount of rapid and hectic efforts from Maya
every time a Sensei died is honestly pretty funny.
However,
if (a big if) these materials left in Sensei's room somehow can persist throughout resets regardless of outcomes, the same way how the urban development in Kumon-mi manages to move through time normally, that means a journal will always be in Sensei's room when he starts and that journal is in fact a relic from many many cycles ago, kinda like a rougelite upgrade.
And I'll throw the same hypothesis at the MM note as well, that this note is a relic from a much much earlier cycle, but Maya did not remember it either due to tampered memory from mechanisms unknown or a failed reset. The order of events would look something like this:
During the very first few cycles, Maya didn't know the password and thus had left the MM note on the wall → Maya lost her memory about this either due to a failed reset or other unknown mechanisms → the note persisted even if its owner didn't → Maya figured about Boobies123 via some BTS means and thus had no need to leave any note of any sort → Maya crafted the journal and left it there after witnessing so many Senseis being miserable on their first day → the journal becomes an item that will always be in Sensei's room when a new cycle starts →
Lessons In Love
Again this is all based on that big
if I have no way of proving it.