Well, a fiction book could be about a character's journey of self-discovery in a contemporary setting. Maybe they're dealing with personal challenges and growth. Another option is a post-apocalyptic story where survivors have to build a new world.
One Hundred Years of Solitude--About the loneliness and search for love
The Great Gatsby: Thoughts on the Dark Side of Society and Human Nature
3 "Three-Body"-about the confrontation between alien civilization and human civilization
Love is always a great topic. You can write about different kinds of love, like romantic love, family love or friendship love. Another topic could be adventure. Stories about exploring new places or going on a dangerous journey can be very exciting.
Love and relationships are great topics. It could be a romantic love story, a story about friendship, or the complex relationship between family members. Mystery is also a good choice. You can create a puzzling situation and keep the readers guessing until the end. And don't forget about writing stories based on current social issues, which can make your work more relevant and thought - provoking.
You can write about the shared memories like the first date, travels together, or the special moments of celebrating anniversaries. These topics are positive and can enhance the bond between the couple.
How about writing a story based on a historical event but adding fictional characters and their perspectives? It combines fact and imagination and can make for a unique read. For example, a story set during the Roman Empire with made-up characters who get caught up in the politics and warfare of the time.