i actually have tried to find them a few months before but came up blank haha.... from my expirience they seem way too stylized to adequately figure out if they even ARE based off anything (the ones assigned to kanade have stems of the same color as the flower - which isnt something that never happens but ive never seen one exactly like that). if I absolutely haddd to i would say hydrangea for kanade, bell flower/some kind of violet for mafuyu and false violets (rubus repens) for miku (mafuyu also holds them in the main illust)... im really sorry if I havent helped you like you hope but thank you for asking anyway.. sorry for the late reply too