The Nogizaka family visits Yuuto's house for a Christmas party. However, the party is cut short when Yuuto faints, having worked himself to exhaustion to buy Haruka a Christmas present. When Yūto regains consciousness, Haruka declares that she will stay by his side in order to nurse him back to health, under the guidance of a very questionable guidebook prepared by Mika. To preserve the Christmas spirit in spite of Yūto's poor health, Haruka decorates his yard with Christmas lights, and presents him with a Christmas present. He in turn presents her with his present: a ring called "Clair de lune" which, at Haruka's request, he places on her ring finger. The two thus share another precious memory together.
今宵はクリスマスイブ。裕人の自宅では、春香たち乃木坂家の面々を迎えてささやかなパーティが催された。大財閥の乃木坂家としては、こうしたホームパーティは初めてで春香は大喜び。美夏たちも大いに盛り上がる。その最中、裕人が過労で倒れてしまう。乃木坂家の医療担当メイド、鞠愛が駆けつけ安静を言い渡される裕人。パーティはお開きとなったが、春香は一人残って裕人の看病をすると申し出た。かくして、思いがけず二人きりの聖夜を過ごすことに……。
누나와 유카리 선생님께서 난동을 부리는 바람에 혹사당하며 일을 하고도 치료비와 변상비로 급료를 다 날려 버린 유토는 하는 수 없이 잡다한 다른 아르바이트를 해서 하루카에게 줄 선물 살 돈을 간신히 마련한다.
