I Kissed my Girlfriend's Little Sister?!

After a month of dating, I finally gathered the courage to hold hands with Haruka—the first girlfriend I had ever had in my life. That small, heart-fluttering milestone should have marked the beginning of a sweet, ordinary romance. Instead, it became the start of a whirlwind I never saw coming. On that very same day, my parents remarried, and I suddenly found myself with a step-sister who looked exactly like Haruka—as though I were staring at my girlfriend's mirror image. Her name is Shigure, and the uncanny resemblance is no mystery at all: she is Haruka's twin sister, separated from her due to family circumstances. Now my hard-won first love has collided with an impossible family twist. One identical face belongs to the girl I am dating; the other belongs to my brand-new relative. With two faces I can barely tell apart and a situation growing more complicated by the day, my peaceful romance is about to be turned upside down in ways I never imagined.