My lovely, utterly autistic and deranged Malware of an oshi (Lia!!!) used to carry around a pink notebook when she was young(er), filled with bullet points, quotes, and mannerisms on how to act like Michiru Matsushima, an archetypal tsundere menhera character from the Grisaia visual novel
Whenever she did something that wasn't "Michiru core," the young Lia would force herself to eat lemon slices, because Michiru would punish herself in the same way in the game, by drinking a fictional super-sour Vitamin C lemon concentrate she would buy from a vending machine.
God I love Lia.