Since it's a light novel about being reincarnated as a hot spring, there could be characters who discover the hot spring. Maybe there's a curious adventurer who becomes a regular visitor and forms a bond with the hot spring in a unique way. He or she might talk to the hot spring as if it has a personality.
There might be a local healer who realizes the special powers of the hot spring and tries to protect it. This character could be interesting as they would have their own backstory related to their healing practices and how the hot spring fits into their beliefs. Also, there could be a villainous character who wants to exploit the hot spring for their own gain, like a greedy merchant who wants to build a resort around it without caring about the hot spring's well - being.
The protagonist is the reincarnated hot spring itself. Then, there could be a local healer who discovers the special powers of the hot spring and becomes sort of a protector or advocate for it. There may also be a group of mischievous spirits in the forest nearby who interact with the hot spring in various ways, either causing trouble or helping out at times.
Well, perhaps the way the hot spring has unique powers or properties that are gradually discovered. For example, it could have healing powers that attract people from far and wide. And also, the relationships the reincarnated hot spring forms with local villagers or other entities in the area. Maybe there's a mystery about the origin of the hot spring's reincarnation that drives the plot forward.
It might be about a person who is reincarnated as a hot spring. Maybe it involves the experiences of this new 'existence' as a hot spring, like how it interacts with the surrounding environment, the people or creatures that come to it, and the unique adventures that can only happen when one is a hot spring.
Well, you might become a character who manages the hot spring. Maybe you'd have to deal with various guests, from nobles to commoners. You could introduce new types of hot spring baths or services to make the place more popular.
One potential enemy could be developers. They might see the hot spring as just a piece of land to build on, not caring about the mc's new existence as the hot spring. Another could be rival natural attractions. If there are other hot springs or beautiful places nearby, they might be jealous of the mc's hot spring getting all the attention and try to undermine it in some way.
Well, it could be about the main character who is reincarnated as a hot spring. Maybe they can communicate with those who come to soak in them, like sharing the stories of their past lives or giving out some mysterious advice. And there might be some sort of adventure as the hot spring tries to protect its existence from those who want to develop the area or something like that.
First, you need to understand the rules of the hot spring. For example, if there are certain taboos about using the hot spring at specific times, you should abide by them. Second, make friends with the local people. They can help you when you are in trouble. Third, try to learn some unique skills related to the hot spring, like making special herbal mixtures for the bath.
In the works of reincarnation in another world, there was a setting where the protagonist was reincarnated into a hot spring. For example, in the light novel "Hot Springs in the Other World"(which could be translated as "I Reincarnated in Hot Springs in the Other World Is Unrivaled in Power"), the male protagonist, Reumi Kasuzu, was originally an ordinary first-year high school student. After he died in a bus accident on his way to the hot springs, he was reincarnated into a small hot spring. He discovered that he could change the temperature and quality of the water. A blonde girl discovered this hot spring and discovered that her magic power had increased after soaking in it, so she became a frequent visitor. The novel "Reincarnated as an Oracle" is equally exciting. Everyone is welcome to click and read it!
The reincarnated aristocrat themselves is an interesting character. Their knowledge from their past life combined with the new challenges in the aristocratic world makes them unique. Then there might be a wise old butler or advisor, who provides guidance and insights to the main character.
The protagonist, of course. As a reincarnated goblin, their journey and growth are central to the story. There might also be a wise elder goblin who imparts knowledge and wisdom to the protagonist. And perhaps a rival goblin who challenges the protagonist's status within the tribe.