As I haven't had the chance to read this 'i tripped into a different world novel', it's hard to say for sure. However, it's common for such novels to have a protagonist who is thrust into this new world. There could be other characters that the protagonist meets, such as a strong and silent warrior type who becomes their ally, or a mischievous fairy who leads them into all sorts of trouble.
I don't know as I haven't read it. But usually in these types of novels, there is a main character who is the one that trips into the different world. There might also be some supporting characters in the new world like a wise old wizard or a friendly beast that helps the main character.
Since I'm not familiar with this particular novel, we can only make educated guesses. It could start with the character tripping, which might be a metaphorical or literal way of getting transported to another world. Once there, they might discover unique abilities within themselves. They could encounter different cultures and societies in this new world. There might be a conflict, like a power struggle or a threat to this new world that the protagonist has to deal with, and throughout the story, they might grow and change as they navigate this different world.
There might be a mentor - like character. This could be an old and wise cook or a magical being who has extensive knowledge about the rare and special foods in the different worlds. They would guide the main character on their journey to discover new ingredients and recipes. And there could also be antagonists, perhaps those who hoard the rare ingredients or try to stop the main character from spreading the knowledge of certain powerful foods.
The main character is the one who gets the cheat ability. There may also be other supporting characters like friends they make in the different world, such as a wise old wizard or a brave warrior who joins them on their adventures.
I'm not sure specifically, but it could be the pharmacist who runs the different - world pharmacy. He or she would likely be the central character driving the story.
There could also be characters in the new world who act as friends or foes to the main character. Maybe there's a wise old man in the new world who becomes a mentor - not in the Naruto - style but still gives useful advice. And of course, there might be antagonists who oppose the main character's rise with the Naruto system, perhaps fearing the change it brings.
In many 'gourmet in a different world light novel' stories, the main character is someone who is passionate about food. They might be a professional chef in their original world or just an enthusiastic amateur. Alongside them, there could be a guide - like a native of the different world who knows the ins and outs of the local food scene. There may also be rivals or friends who join the main character on their culinary adventures in the different world.
Without more details about the particular 'lonely attack on the different world novel', it's impossible to accurately name the main characters. But in general, the main character might be someone who has been somehow separated from their normal life and thrown into this different world. They could be a loner type, someone who is used to relying on themselves. There might also be other characters like a guide figure who appears later to help the main character navigate the new world, or an antagonist who tries to stop the main character's 'attack' or progress in the different world.
There could be a group of characters. One might be a creative type, like an artist or a writer, who is constantly inspired by the new and strange things in the different world. Another could be a bit of a loner, but they slowly open up as they experience the unique charm of the different world. And there could be a character who has a special ability that helps them navigate and understand the different world better, and together they form the main characters in this 'chillin different world life novel'.
Since I don't know the details of this novel, I can't say for sure who the main characters are. But it's likely that there's the karate - practicing character who is the protagonist.
In some 'working in a different world light novels', there are also characters that are native to the different world. They could be friends or allies of the main character, or they could initially be suspicious of this outsider who has entered their world. Their cultures and values would be different from the main character's original world, which would lead to interesting interactions.