Outline for a story: A young adventurer discovers a hidden cave. What could be inside the cave?

Perhaps there are some strange creatures living in the hidden cave. These creatures might be new species that no one has ever seen before. They could have unique abilities, like being able to control a certain element or having the power to heal. Naruto might have to figure out how to deal with these creatures, either befriend them or find a way to avoid them if they are dangerous.

There could be a hidden jutsu scroll. Maybe it was left there by a powerful ninja long ago. Naruto might discover some new and unique techniques that could help him in his battles or in his journey to become Hokage.

Well, without having read the 'inside the cave light novel', it's hard to say for certain. However, based on the title, it may involve themes such as isolation, discovery, and survival. The characters could be trapped inside the cave and have to find a way out while also dealing with whatever lurks in the darkness. There might also be elements of self - discovery as they endure the hardships within the cave environment.

Based on my lack of prior knowledge about this particular light novel, it doesn't seem to be one of the mainstream popular ones. But popularity can be a relative term. In some specific circles or communities that focus on certain types of stories or settings, it could be quite well - regarded. Maybe it has some really interesting characters or a very original plot that could attract readers, but as of now, it's not on the radar of most general light novel readers.

One possible theme could be exploration. If it's about the first cave, the idea of venturing into the unknown is a strong theme.

The darkness. In a cave, there is often little to no natural light. This complete or near - complete lack of visibility can be extremely frightening as you can't see what might be lurking around you. It plays on our fear of the unknown.

There could be a little fairy. The fairy might have lost her way and found the empty cave. She could use her magic to create a soft bed of moss and flowers to sleep on. Maybe she'd also make some twinkling lights to make the cave feel cozy at bedtime.

Not having read the 'inside the cave light novel', it's difficult to name the main characters. But considering the setting, it might be a group of spelunkers. One of them could be a scientist interested in the geological formations inside the cave. Another could be a thrill - seeker who just wants the excitement of exploring the unknown. And perhaps there's a local guide who has some family legends about the cave and is guiding the others. Their interactions and individual goals would likely drive the story forward.

He might encounter hidden treasures or ancient relics.

The 'first cave cave story' is rather ambiguous. It might be a made - up name for a story. It could potentially be about the experiences of the first people who entered a particular cave, like their adventures, the things they saw inside, and how they coped with the unknown environment of the cave.