Z's Life (Volume Z)
Z entered the Naval Academy. He wanted to be a hero.
He took part in actual fighting for the first time.
Z was promoted to petty officer. He mastered Rokushiki. He realized that Marine is not always a hero.
He began to be called "Black Arm". He was the master of Armament haki.
He was promoted to Admiral. Zephr was popular among his subordinates. Roger and Whitebeard were in their golden age at that time.
Z's son was born.
Z's family were killed by a pirate. Z intended to resign Marine, but higer officer persuaded him to stay Marine. Z became an instructor.
Akainu (age 23) and Kizaru (age 26) joined Marine. Both of them were already "Monsters".
Aokiji (age 19) joined Marine.
Z gave strict lessons to his disciples.
A pirate cut Z's arm off.
A Marine scientist gave "Battle Smasher" to Z.
The pirate who had cut Z's arm off joined Shichibukai.
Luffy beats Z.
It seems that the pirate who cut Z's arm off is a new character who joined Shicibukai one year ago.