i just want to know what caused the memory loss
yea..me too
They hinted that it might be because of some kind of emotional shock or trauma, but actual trauma would be pretty out of place with the mood of the series, so I'm guessing Arisa mistook a situation and throught Mari was cheating on her, or was going to leave, or something, but it turns out to be a misunderstanding.
to find out now that the trauma was actually her woman asking her to marry her is honestly in my book a pathetic reason to lose your memories but it is also quite cute as well
this way too cute!! damnn arisa idiot and best gift ever , Lol