She is a 《mob》.
Actually, she is supposed~ to be a 《mob》.
But in her own story, wouldn't she be a 《heroine》?
A story about a girl who has a unique magic and with that magic, she somehow stumbles upon a man-made creature called 『tablet』 which has an otome game called 「Otouto’s Affection」.
As she plays that game, she realizes that her world was as same one as the world inside the game and she has a mob role in the game. Thus, as a romance story lover — she claims herself — she is determined to watch the romance unfolded with her own eyes.