Maestru has fair skin and blue-green eyes. His hair is black with several gray streaks. He wears a black bow tie.
Maestru is Oobi and Kako's singing teacher. He can get impatient if his students do not listen to his instructions, but overall, he is a respectful person. Maestru can play the piano and the keyboard, similarly to Inka.
- Maestru's design was most likely inspired by Beethoven's appearance.
- Nick the waiter, a minor character seen in the "Chopsticks!" episode, wears a bow tie identical to Maestru's.