The title 'yuusha shoukan ni makikomareta light novel' gives some clues. 'Yuusha shoukan' is hero summoning. 'Ni makikomareta' could imply being involved in or caught up in. So it might be a light novel where the story is centered around a character who becomes involved in the summoning of a hero. This could lead to a whole series of events. For example, the character might be an ordinary person who is suddenly thrust into a world of magic and heroics. They could be a bystander who gets dragged into the hero's journey, or they might have a special role to play in the summoning process that they were unaware of. It could also involve the hero having some sort of special power or mission, and the character who is caught up in the summoning has to either help or hinder the hero's progress.
Well, 'yuusha ni narenakatta light novel' could potentially revolve around the struggles of someone who has the aspiration to be a hero (yuusha in Japanese) but for some reason, can't achieve that status. Maybe it's due to lack of power, or some external factors that keep hindering the protagonist's journey to heroism. It could also explore the psychological state of this person who has this unfulfilled dream.
I'm not sure specifically as I haven't read this light novel. But generally, 'yuusha' means 'hero' in Japanese. It might be about a hero who has something 'zenbu ubawareta' which could mean 'has everything taken away'. It could be about the hero's journey after losing everything.
Well, without having read the actual 'zettai ni yatte wa ikenai isekai shoukan novel', it's difficult to give a detailed account. However, given the title, it could be about a character who is summoned to an isekai world and discovers there are certain actions that are strictly prohibited. Maybe it involves a protagonist who has to navigate this new world while avoiding these forbidden deeds to achieve a certain goal, like saving the isekai or getting back home.
In the 'jujutsushi wa yuusha ni narenai light novel', their social status and perception are different. Jujutsushi are part of a more hidden and often feared world. They are not always seen as heroes in the eyes of the general public. Yuusha, however, are typically celebrated and seen as saviors. Also, their approach to problems varies. Jujutsushi might use more complex and sometimes unethical methods to deal with curses. Yuusha, generally, use more straightforward and morally - upright ways to face challenges.
The jujutsushi in the light novel might not be able to become a yuusha because of their origin and training. Jujutsushi are trained in the ways of jujutsu, which often involve a lot of secrecy and self - preservation within the jujutsu community. A yuusha, on the other hand, is usually more outward - looking and ready to sacrifice for the greater good. Their upbringing and the environment they are in play a big role in determining whether they can transition into a yuusha - like figure.
As I'm not familiar with this specific 'zettai ni yatte wa ikenai isekai shoukan novel', there's no way for me to determine the main characters. It could be a typical isekai setup where there's a young male or female protagonist who gets summoned to the other world and has to face various challenges, but without reading it, this is just speculation.
Online platforms such as Amazon Japan might be a good place to start. They have a wide range of Japanese light novels available for purchase. Also, some specialized e - book platforms that focus on Japanese literature could also have it.