Since I don't know which 'black ocean novel' you're referring to, I can't say for sure who the main characters are. They could be fishermen, sailors, or scientists.
There's no way to determine the main characters without more information about the 'black ocean novel'. But they might be adventurers seeking something in the black ocean, like a lost treasure or a way to save the world from an ocean - related threat. Or they could be ordinary people who are thrust into extraordinary situations in the black of the ocean.
Since the title has the idea of 'a drop in the ocean', the main characters might be ordinary people who find themselves in extraordinary situations. Maybe it's a family of sailors who feel small against the might of the ocean. Or it could be a writer who comes to a seaside town to find inspiration and discovers that his or her presence there is like a drop in the ocean of the town's rich history and complex social fabric.
Without having read the 'dragon ocean jewel novel', it's hard to say for sure. However, if we go by the title, the dragon is bound to be a major character. There could be a group of sailors or pirates who stumble upon the knowledge of the jewel in the dragon's territory in the ocean. Among them, there could be a brave leader who emerges as a main character. And there might be a wizard or a sorceress who has some connection to the jewel, either trying to protect it or use it for their own magical purposes.
The main character is an unnamed man who revisits his childhood memories. There are also the Hempstocks, a family of women who play important roles in the story.
I don't know the specific main characters in 'paradise ocean visual novel' since I haven't read it. But they could be ocean explorers, like a young and brave sailor, or a marine biologist who is passionate about the ocean.
The main character is Fayt Leingod. He is crucial to the story as he drives the plot forward with his actions and decisions.
The main character is Claude C. Kenny. He plays a crucial role in the story.
There may not be other obvious main characters mentioned in just 'the boy and the ocean story'. But sometimes, there could be seagulls or other sea creatures that play a minor but important role in the boy's experience with the ocean, which could potentially be seen as secondary characters.
I'm not certain without more specific information about which 'Star Ocean Story' it is. But usually, there are brave heroes, perhaps a young protagonist with special abilities.
The main characters include Claude C. Kenny, a young man with extraordinary abilities. There's also Rena Lanford, a kind - hearted girl from the planet Expel. They are central to the story's development.
The main character is an unnamed man who is reminiscing about his childhood. There is also Lettie Hempstock, a young girl with a special connection to the otherworldly elements in the story.