I Still Don't Know About My Favourite Character's Unwavering Obsession summary:

"I have no regrets about dedicating my life to supporting my favorite...!"Asuka, a teacher in her 30s, finds her purpose in life by being devoted to Alexandrite, a character from a romance game. After discovering in the anime adaptation that Alex dies on another route, Asuka is so devastated that she passes out. When she wakes up, she has been reincarnated as a mob noblewoman, Arianell, inside the game world. Determined to prevent her favorite's death, Arianell pretends to be a villainess and plots to pair Alex with the game's heroine. However, Alex becomes obsessed with Arianell instead! To make matters worse, Alex's younger brother, Citrine, also becomes infatuated with her..."For me, your existence is nothing short of a miracle...""Mark my words, I will make you mine."