"Grand Duke is one of the main characters in the Japanese manga ""Under the Oak Tree"". He is a nobleman and a member of the royal family. Grand Duke is a charismatic and powerful figure who is highly respected and feared by those around him.

Grand Duke is first introduced in the manga as a cold and calculating character who holds a lot of power and influence within the kingdom. He is known for his sharp mind, cunning tactics, and strong leadership skills. Despite his intimidating presence, Grand Duke is also shown to have a softer side, especially when it comes to the female lead, who he falls in love with.

Throughout the manga, Grand Duke is portrayed as a complex character with a rich backstory. He is shown to have had a difficult childhood, which has made him emotionally guarded and distrustful of others. He is also deeply loyal to his family and is willing to go to great lengths to protect them.

As the story progresses, Grand Duke becomes more involved with the female lead, and it is revealed that he has a strong sense of honor and justice. He is willing to put his own safety at risk to protect others, especially those he cares about. Grand Duke also shows a softer side when he is with the female lead, and their interactions are often sweet and tender.

Overall, Grand Duke is a multifaceted character who is both a formidable adversary and a loyal friend. He is a complex and intriguing character who is a central part of the storyline in ""Under the Oak Tree"" and is sure to capture the hearts of readers."