NAKAIMO - My Little Sister Is Among Them!

After the death of his father, Shougo Mikadono is set to inherit the Mikadono Group once he completes his preparation. There’s one condition attached to taking the helm: during high school, he must choose someone he truly loves and be ready to marry her by graduation.

Shougo transfers to Miryuin Private Academy and quickly finds himself surrounded by several standout girls, including class representative Konoe Suruma, the guarded yet considerate Miyabi Kannagi, student council vice president Rinka Kunitachi, café worker Mei Sagara with her witchlike style, and student council president Mana Tendou. But an unsettling twist complicates every budding romance—one of them is his long-lost half-sister, and Shougo has no idea who, turning his search for love into a tangle of suspicion, attraction, and unanswered questions.