The plot involves Rimuru's journey from being a rather weak (initially) slime to becoming a very powerful being. He meets many interesting characters. For example, there are the goblins he befriends early on. Rimuru helps them improve their living conditions. As the story progresses, he also has to deal with the threat of other more powerful monsters and even some human kingdoms that view his growing power with suspicion. In general, it's a story full of adventure, growth, and the forging of relationships in a magical and dangerous world.
Nero Wolfe in 'rex stout nero wolfe complete 47 novels' is a very unique detective. He is overweight and prefers to stay in his home most of the time, but his mind is sharp as a tack. He uses his deductive skills to solve various mysteries, often relying on his assistant Archie Goodwin to gather information for him. He has a passion for orchids and a refined taste in food, which are some of his distinct characteristics.
The main character is Rimuru Tempest. He is a slime who has unique powers and a great deal of charisma. Another important character is Veldora, the storm dragon who befriends Rimuru. There is also Shizu, a human who has an impact on Rimuru's early development. And then there are characters like Benimaru, a powerful ogre who becomes one of Rimuru's loyal followers.