"What the hell does that baby in your belly have to do with me?" Nico is not only a prince of Niroli but also a working architect in London. His secretary, Carrie, gave in to Nico's pushy seduction knowing that it would only be a one-night stand. Three months later, she learns that she's pregnant. Meanwhile, Nico has been called back to his home country due to a dispute over who will be heir to the throne. Full of unease and hopes, Carrie and Nico are reunited at the royal palace. But what's waiting for her there are Nico's cold words and his beautiful fiancée!

Part of the Niroli Rules series (ニローリ・ルールズシリーズ), also called "The Royal House of Niroli" series, which goes as follows:

1. Itsuwari no Kamen
2. Doctor wa Prince
3. Prince to Scandal
4. Chichuukai o Wataru Kaze
5. Tsumetai Prince
6. Kokoro no Symphony
7. Yuuwaku no Perfume
8. Oujo no Unmei