In some 'isekai ojisan light novel', there could be antagonists as well. These could be powerful mages or demons who oppose the ojisan's actions in the isekai world. Their presence adds conflict to the story, forcing the ojisan to use his wits and whatever skills he has to overcome the challenges they pose.
The main character is the ojisan, of course. He is usually an older man who gets transported to another world.
Often, there are other supporting characters in the 'isekai ojisan light novel'. For instance, there might be young adventurers who the ojisan teams up with. These characters are usually amazed by the ojisan's different way of thinking which comes from his real - world experiences. They help the ojisan in his adventures in the isekai world and also learn a lot from him in the process.
One popular 'isekai ojisan light novel' could be 'Isekai Ojisan: Isekai ni Tensei Shita Kedo Cheat Nanka Shinai yo'. It tells an interesting story about an uncle who gets isekai -ed but doesn't have the typical cheat skills.
I'm not sure who the main characters are exactly as I don't know this work well. But from the title, it seems that a bishoujo and an ojisan would be important characters.
As I'm not familiar with the 'isekai shokudou light novel' in detail, it's hard to name the main characters. However, thinking about the common setups in isekai stories, there could be a kind - hearted character who manages the shokudou and acts as a sort of anchor in the story. There might also be characters who bring different cultures and powers from their own isekai worlds, and their interactions with the shokudou environment and other customers form the core of the story.
The main character is Touya Mochizuki. He gets transported to a different world and has his smartphone with him, which he uses to his advantage in this new world.
There are characters from different isekai works. Such as Ainz from Overlord, Subaru from Re:Zero, Kazuma from Konosuba.
Since I don't know the details of this particular light novel, it's hard to say. But in most isekai light novels, there's usually a main character who is the one transported to the other world. This character often has some distinct traits that help them survive in the new environment.
Since I don't have first - hand knowledge of the 'isekai no seikishi monogatari light novel', it's hard to say exactly who the main characters are. However, based on the genre, there could be a young male or female protagonist who is the key figure. They may encounter a group of diverse companions, such as a strong - willed warrior, a clever thief - like character, and a gentle healer. These characters would then accompany the protagonist on their adventures in the isekai world.
Since I haven't read 'Tensei Kizoku no Isekai Light Novel', I can't name the main characters specifically. But typically in an isekai light novel like this, there would be the protagonist who is the reincarnated noble. There might also be side characters like a mentor figure who helps the protagonist understand the new world, or rivals who oppose the protagonist's goals in the new world.
In 'Overlord', the main character is Momonga. He was once a normal player but becomes the all - powerful Overlord in the game - turned - real - world. In 'That Time I Got Reincarnated as a Slime', Rimuru Tempest is the protagonist. He starts as a slime but gains many powers and friends along his journey. In 'KonoSuba', Kazuma Satou is the main character, a NEET who is transported to another world and has to deal with all kinds of wacky situations.
There could also be a mentor - like character. In many isekai stories, the protagonist meets someone who helps them understand the new world, its rules, and how to use their new - found abilities. This character might be a powerful wizard or an experienced adventurer in the context of the 'isekai meikyuu no saishinbu light novel'.