Nakaimo: My Little Sister Is Among Them!

Shougo Mikadono's father has recently died, leaving him to inherit the leadership of the Mikadono Group, his father's company. After finishing the necessary training to take control, there's one final condition he must meet: before graduating high school, he has to find a girl he loves at his new school and marry her. Shougo enrolls at Miryuin Private Academy, where several potential candidates catch his eye-Konoe Suruma, the class rep and his first friend; Miyabi Kannagi, distant yet warmhearted; Rinka Kunitachi, the vice president of the student council; Mei Sagara, who manages a cafe and wears witch-like outfits; and Mana Tendou, the student council president. But there's a problem: one of them is his unknown half-sister. With no way to tell who it is, how can he risk falling for any of them?