Luna Knight 

High schooler Luna Amano can barely recall the last 5 years of her life. Her older sister promised to help Luna make new memories—until one day, she vanished. Alone with few memories to cling to, Luna dedicates herself to keeping up her sister's shop in hopes she one day returns. After receiving threats from her yakuza landlord, Luna returns home one day to find the flower shop up in flames! Suddenly, everything shifts, and hazy memories flood her mind. In a flash, Luna goes from seeing red to painting the streets red with blood. She doesn't know why she's so capable with a gun, but what she does know is that she will not forgive the men who started the fire.