Shogo Mikadono, heir to the Mikadono Group, enrolls in Miryuin Private Academy, also having to find his potential wife there. He saves a girl named Konoe Tsuruma from a oncoming truck outside a bakery, and she later shows him to his homeroom class after they briefly share cream puffs at a park. Shogo explains to Konoe that he received a scar on his forehead after an accident as a child. After Konoe is summoned to a student council meeting, Miyabi Kannagi tries to make a move on Shogo, but he backs out of it. Later at night, he receives a birthday cake and an action figure by mail. After seeing a photo of him as a child being kissed by an unknown girl at an amusement park, he receives a phone call from this girl confirming this. The next morning, he ponders if the girl who chooses to marry will end up being his little sister.