A fully grown adult male despite his short stature and boyish appearance. His age is unknown, but considering his close friend Viktor von Granzreich is likely in his late 30s to early 40s based on his appearance and the era, Heine is almost certainly around forty.

The First Prince. 23 years old. Viktor's eldest son and the oldest of the brothers. Though often mentioned as a brilliant prince, he has had very little screen time, so little is known about him. He appeared in the final episode of the anime, observing the meeting to hire a royal tutor for his younger brothers.

The Second Prince. 17 years old, equivalent to a high school junior. He is tacitual and has sharp, fierce eyes, with one eye covered by his hair. While preliminary reports described him as a lonely and rough individual, he is actually a childlike character who loves cute things, soft textures, and nature.

The Third Prince. 16 years old, equivalent to a high school sophomore. A glasses-wearing intellectual. He was initially polite to Heine, but his expression changed when he learned Heine had never attended a university. However, after confirming Heine's abilities through an interview, he became completely devoted to him, calling him 'Master' instead of 'Teacher.'

The Fourth Prince. 15 years old, equivalent to a middle school senior. Blonde hair and blue eyes. He has immense pride. Known as the 'Everest of Superiority,' he showed the strongest hostility toward Heine during their first meeting. A physical powerhouse who hates studying, he has bullied and escaped from every previous royal tutor, and none could catch him. Though not academically gifted, his athletic reflexes and stamina are exceptional, allowing him to sweep trophies in running and horse racing.

The Fifth Prince. 14 years old, equivalent to a middle school junior. Long-haired and innocent. During his first meeting with Heine, he acted un-royally by picking up the small-statured Heine and spinning him around, even telling him to use the nickname 'Licchi' because his name is too long. He loves women and frequently brings girls from the city into the palace.

The King of the Granzreich Kingdom. He invited Heine to become the royal tutor by letter. Considering his eldest son is 23, he must be at least in his late 30s or early 40s, yet he possesses beauty that rivals his sons. He ascended the throne at 18, the youngest in the kingdom's history, and soon turned the military into the strongest on the Western continent, earning the title 'God of War,' yet he is a doting father who is weak for his sons.