Кто пошел изучать понятие "Исекай", тот я

Умные люди говорят, что "Исекай" - это японское название для попаданцев. Не одними родными осинами стоит сей прекрасный жанр, да-да. 

This is the way isekai novels should be written.  (если трудно, там внизу в комментах перевод есть)

The genre of isekai (Japanese: different world) literature is, in essence, a lab experiment on a character. The protagonist of isekai novel is usually reincarnated into another body in a different world, or in rare cases teleported there.

I will be too simplistic here and say that a good novel has a protagonist or a supporting character that you, the reader, cheer for. Maybe not wholeheartedly, maybe not in the beginning, but close to the end. When there is 'nobody to love', the novel usually flops. A typical isekai novel makes it easier to cheer for the main character because they are literally surviving on their own in a completely unknown universe. It is essentially a double win - take an average character from the crowd and drop them into another world to conquer it and our hearts in one fell swoop. At the middle of a typical isekai the protagonist either finds out that their body have superpowers or that he can become super rich by selling cake recipes that are somehow completely unknown in the world they ended in.

The novel "Silver" does something totally opposite. It takes a soul of a woman that is, hopefully, from our world (there is no direct evidence to be either case) and makes her a 'soulmate' of a young girl from Argentine of year 1896. The Argentine of 1896 is similar to life you live in, but all the little details make it hauntingly different, like a world's reflection in a weird mirror.

And this is where isekai, designed to show off travels of a soul, begins to shine. To begin with, author is silent on the protagonist's pre-death life circumstances - the 'soulmate' is a black box that we can only glimpse into by her actions, even though the entire text is written from her point of view. It is very Christian concept - know them from their deeds, and it is the protagonist's deeds that made a lot of difference and likely saved not just one, but multiple souls while doing what seems a very mundane thing - building a family.

Where the average isekai novel dives into exploration of the setting, the "Silver" shows how transformation of the soul changes the world around, much like in our regular modern day lives. Fortunately, you don't notice the trick until you are done reading the epilogue.