Taken into the demon realm at only 17 years old, Kaigaku learned a lot under his mentor Kokushibo. One of his main lessons was respect and discipline for his attitude and snappy mouth towards everyone.

Kokushibo’s training was harsh, and out of place when Upper Moon One’s wanted it to be. Wanted him to learn from pure exhaustion and confusion when met in a difficult battle against a slayer. Kaigaku used to be a slayer himself and trained underneath the former Thunder Hashira… though his morals have changed since then.

The cold gream of the Demon realm—Infinity Castle was his mainstay because of Upper Moon One’s command to keep him in one spot until the demon had perceived him as able enough to leave. He was only considered a baby demon after all. Newly formed.

~

"Tch, you’re just dirt." Kaigaku scoffs at the lower moon in front of him, his turqoise eyes looking into theirs as he glares at them. He felt high and mighty, seeing how he was the new Upper Moon.