— Nobukazu Takenaka's last words to Nazuna, some months after her training has finished.
Sensei Nobukazu Takenaka (2 March 1867 - 18 August 2018) was a Japanese quail who taught Nazuna and her father swordfighting, and is the second great-grandfather of Akio Tsukuda. He died at the age of 151 watching Nazuna meet the peak of her abilities, and his spirit rests in her Jadesabre.
Nobukazu was described as being very patient with his students. He was often seen meditating in the ancient Murahara temple, located at the edge of a mountain. Nobukazu spoke in a low and soft voice, and rarely yelled. He was in absolute composure, no matter what was facing him.
Nobukazu Takenaka was born to a single mother; his father was killed trying to protect him months before he was born.
===Martial arts ===
As Nobukazu was incredibly old, he was frail. As a result, he wasn't as agile as he used to be, and was vulnerable to sickness and somnolence.
- Nobukazu was not immortal when he died. As a matter of fact, through prolonged meditation, Nobukazu increased his lifespan by nearly 2 times the life expectancy in East Asia.