How A Realist Hero Rebuilt The Kingdom Vol. 4 (Light Novel)

In Vol. 4, after the war with the Principality of Amidonia, provisional king Kazuya receives an unexpected message. To his surprise, his former enemies in the Principality are requesting annexation. Due to the country facing a civil war and invasion from neighboring countries, the Principality is seeking the Kingdom of Elfrieden’s help to fight back. Kazuya agrees to the annexation and calls for those with an important role in the defense of the Principality to convene in Van. Hiding among them, however, is the Princess of the Principality, Roroa, who unexpectedly asks for Kazuya’s hand in marriage! What will Kazuya do about her sudden proposal?
Notice: This book is written in Japanese.