Also known as: 乃木坂春香の秘密
A 2004-current light novel series by Igarashi Yuusaku, with illustrations by Shaa, published ASCII Media Works' Dengeki Bunko imprint. Also adapted into a 2006-10 manga serialized in Dengeki Moeoh, with illustrations by Miyama Yasuhiro, visual novels, and two 2008-2009 anime by Studio Barcelona.
Characters
- Alistia Rein
- Amamiya Shiina
- Asahina Mai
- Asakura Nobunaga
- Ayase Ruko
- Ayase Yuuto
- Kamishiro Yukari (Nogizaka Haruka)
- Nagai (Nogizaka Haruka)
- Nanashiro Nanami
- Nogizaka Akiho
- Nogizaka Gentou
- Nogizaka Haruka
- Nogizaka Mika
- Ogawa (Nogizaka Haruka)
- Sakurazaka Hazuki
- Sawamura Ryouko
- Takenami (Nogizaka Haruka)
- Tennouji Touka
- Yatsusaki Setsuna
