Didn't I Say That We're Doing Everyone's Backstories?! - S1.E5

Reina reveals her past... Memories of a tragedy that torments her still. Then Pauline reveals her past, and Mavis reveals hers too. Then, suddenly, Mile gives confirmation of her past as well. Up until now, she's managed to gloss things over, but the truth of her reincarnation into another world is here! And, of course, "those girls" will make an appearance too!