I'm not sure specifically what 'Cap deage' means. It could be a very specific term, a misspelling, or something relatively unknown. It might be a proper name, a local term in a certain area or a very niche concept.
I'm not familiar with the 'makai kaeri no rettou nouryokusha light novel'. However, light novels typically blend elements such as fantasy, adventure, and sometimes romance. It might be about a hero's journey in a mysterious world, or it could center around a group of characters with special powers trying to achieve a certain goal in a unique setting. Without reading it, it's hard to say for sure.
I don't have enough information to say exactly who Cap'n Kathy is. She could be an original character created by the fan fiction writer. Maybe she's a pirate - the 'cap'n' part could suggest that - who has some connection to the wizarding world of Harry Potter.
Cap cartoons are known for their creativity. They might have unique settings or fantasy elements. They often aim to entertain and capture the attention of the audience with their lively visuals and engaging stories.
You can try looking for it in local bookstores that specialize in Japanese literature or light novels. They might have it in stock or be able to order it for you.
A cartoon shower cap is known for its eye-catching appearance. It can be in various shapes like animal heads or funny objects. Also, it's usually elasticized to fit different head sizes snugly.
The cap man and monkey story is an interesting one. There was this cap man who was traveling around selling his caps. He reached a place near a forest and decided to take a rest under a tree. While he was sleeping, the monkeys in the tree noticed the caps. They climbed down, grabbed the caps, and went back up the tree. When the man woke up, he was confused at first, then saw the monkeys with his caps. He was worried as those caps were his livelihood. But then he remembered that monkeys often mimic human actions. So he took off his own cap and tossed it. The monkeys, being the imitators they are, did the same with the caps they had taken, and the cap man got his caps back.