Osana Najimi might also be a popular character. She can be involved in the fanfiction as a friend or foe to Midori. If the story is set in the school environment typical of Yandere Dev's work, Osana could play a significant role in the power struggles or relationship dynamics. Additionally, Info - chan could be included. She has her own mysterious nature, and her interactions with Midori could be full of intrigue and mystery.
I'm not entirely sure specifically as there could be various themes in it. It might be about a character's unique journey, perhaps with elements of mystery, action or personal growth. But without reading it, it's hard to say precisely.
Friendship is a common theme. They often start as friends and then develop a deeper bond. Another theme is growth, both as individuals and in their relationship.
Without having read her works, it's hard to say exactly. But in general, an author's unique touch in science fiction can come from their world - building. Maybe Takase Midori creates really immersive and different future or alien worlds.
One interesting story could be about a player who discovers a hidden path in the hitori kakurenbo game. This path led them to a special area where they found rare items that helped them progress further in the game.
Another option is to check with local libraries. Some libraries have sections dedicated to international literature or manga/light novel collections. They might have a copy of 'hitori no shita light novel' that you can borrow and read. If your local library doesn't have it, you could request them to acquire it.
The 'isekai de tada hitori light novel' could potentially be about a solitary adventure in an isekai world. It might follow the journey of a character who finds themselves alone in a strange new world, perhaps facing various challenges, making new discoveries, and growing as a person while dealing with their solitude.
I don't have information about the author of this 'isekai de tada hitori light novel' at hand. You may need to search for it in specialized light novel databases or websites.