After that training, a month had passed. During this time, Kai, having received permission from Sakazuki, earned the rank of Recruit. His work involved helping the other Marines carry equipment. Each day started the same way: morning duties, followed by physical training and sword practice, then lunch at the Cafeteria, and finally training with Kairoseki and the stone.
Kai also began sparring with Momongo, and sometimes Oniguma joined them. From their very first battle, Kai and Oniguma developed a strong dislike for each other. Kai even considered fighting Sakazuki, but he realized that a single strike from him would send Kai flying, giving a harsh lesson.
Meanwhile, Sakazuki gazed thoughtfully out the window. Two months had passed, and he was supposed to return to Marineford, but he wanted to stay and continue training Kai. Suddenly, Momongo entered the room:
— Vice Admiral Sakazuki, I spoke with Admiral Sengoku. He ordered you to return to Marineford as soon as possible.
Sakazuki was shocked.
— You… could become an Admiral. Right now, in the New World, pirates are becoming extremely dangerous: Kaido, Big Mom, Borsalino, and the World Government has established the Shichibukai system. The Marines are feeling the tension, and now is the perfect time for you, Kuzan, and Borsalino to become Admirals.
Sakazuki looked at Momongo:
— You're coming with me?
— Yes. Sengoku ordered that Oniguma and I return as well, — replied Momongo.
— Very well. Momongo, prepare your things. Tomorrow we leave for Marineford.
— And what about Kai? — asked Momongo.
— No. In Marineford, too many eyes will be on him; it could weaken him. He will stay here. When he grows stronger, I will take him with me, — said Sakazuki.
On the training field, Kai was sparring with Oniguma. When their swords clashed, one of Oniguma's hands pulled out handcuffs made of Kairoseki and fastened them on Kai.
— Hey, stinky spider! Stop using Kairoseki and fight like a man! — shouted Kai.
— Shut up, little brat! Fighting is never fair. Shigan — Finger Pistol! — Oniguma shouted and struck Kai's shoulder. Kai weakened and fell to the ground.
Oniguma snorted and left. Kai lay there thinking: This guy is going to make me suffer a lot.
Unlike Oniguma, Momongo always fought honestly. Even when Kai used his Devil Fruit powers, Momongo didn't complain and continued to fight fairly. Thanks to this, Momongo improved his Observation Haki and Armament Haki.
Suddenly, Kai heard footsteps and felt someone lift him from the ground and remove the handcuffs. It was Sakazuki.
— Oniguma used Kairoseki again, huh? — Sakazuki smirked.
— I promise, one day I will make him suffer a lot, — Kai snorted.
— Kai, I need to tell you… I, Momongo, and Oniguma are returning to Marineford, and you are staying here, — Sakazuki said.
Kai lowered his head:
— Sakazuki-san, please take me with you. I've grown stronger and won't get in your way.
Sakazuki placed a hand on Kai's head:
— You are still not ready. But don't worry, I will return for you when you become stronger and take you to Marineford.
Hearing this, Kai said nothing. He only swore to himself that he would train even harder.
Kai: So Senior Momonga and that stinking spider are going with you too…
Sakazuki ignored the way Kai referred to Onigumo and nodded as he said:
"Yes, they are going with me as well. They may become Vice Admirals. Chaos is spreading more and more in the New World, and it must be stopped. But don't worry — the new person who will be in charge here is Yamakaji. He was recently promoted to Rear Admiral. He is very strong in hand-to-hand combat, skilled with the sword, and has excellent mastery of all Six Powers of the Marines. I will tell him to train you — you are ready to start learning them."
Hearing this, Kai smiled and said:
"Good luck, Sakazuki-san. Show the pirates of the New World what it means to cross the Marines."
After saying that, Kai bowed and continued:
"Thank you for everything you've done. I promise I will keep training and become stronger."
Sakazuki smiled and, without saying another word, walked away.
Some time passed, and the day came for Sakazuki to depart for Marineford. Kai stood on the pier, feeling Sakazuki, Momonga, and that bastard Onigumo board the ship and set sail. Kai remained there until he could no longer feel the ship's presence at all.