You could also rewrite a particular chapter or event from the game from a different perspective. Say, instead of the hero's point of view during a battle, write it from the enemy's side. What were they thinking? What were their motives? This can add a whole new layer of depth and intrigue to the fanfic.
One idea could be exploring an alternate universe where the Spirits and the main character have different initial meetings. For example, instead of meeting in a battle - like situation, they meet in a peaceful school event. Another plot could involve a Spirit who has lost her powers and the main character has to help her regain them without using the usual methods. It could lead to a whole new adventure and deeper understanding between them.
One idea could be exploring an alternate universe where the spirits have different powers and relationships. For example, making Tohka have the power to control time and seeing how that changes her interactions with Shido. Another could be a story focused on the backstories of the spirits before they became spirits, like what Kurumi's life was like as a normal human. Maybe a fanfic where Shido has to go through a series of trials to prove his love for the spirits in a more extreme way than in the original story.
One idea could be to create an OC who is a transfer student with a unique musical talent like playing a rare instrument. Another could be an OC who has a mysterious past related to the idol world and slowly reveals it throughout the fanfic. You could also make an OC that has to overcome a big obstacle like stage fright to achieve their idol dreams.
A plot could involve a mystery where the characters are bound by a strange occurrence. Maybe there are strange disappearances in the idol world, and they have to use their skills and friendship to solve it. It would add an element of suspense and also show how their love for the idol life and each other helps them through tough times.
Perhaps in the fanfic, one of the members has become a successful solo artist but is feeling a bit lost and lonely. The reunion is proposed as a way to regain that sense of purpose and connection. They all come together, and during the process, they share their individual experiences since the group disbanded. This leads to a deeper understanding among them and a new start for the group, not just in terms of performing but also in their personal relationships.
Another interesting OC could be a spirit who has the ability to communicate with animals. This OC could bring a whole new dynamic to the story as she tries to understand the human world through the eyes of the animals she befriends. She might also use her animal friends to help Shido in his missions, like having birds spy on the AST or something.
One idea could be that the main character has memories of their past lives and uses that knowledge to change the fates of the Spirits in a more positive way. For example, they might be able to prevent some of the more tragic events that usually occur in the original story.
One idea could be a character who was on the verge of death in the original story gets a second chance and has to deal with the moral implications of their new life. For example, if they were a villain before, they might struggle with whether to continue their evil ways or start anew.
A great plot for 'a life to live fanfiction' could be a crossover with another similar show. Imagine characters from 'a life to live' interacting with characters from another well - known soap opera. There could be all kinds of drama as they deal with different cultures, values, and storylines from the other show. It would be exciting to see how the characters adapt and what new relationships and conflicts would arise from this unique combination.
Well, you could have a plot where Kurumi gets trapped in a dream world created by another entity. In this world, she has to face her deepest fears and insecurities. As she battles through this, she discovers new aspects of her powers. Or there could be a fanfic where Kurumi is accidentally sent to a parallel universe where things are very different, and she has to find her way back while also dealing with the differences in that universe. Also, a story about Kurumi sharing her experiences with a young spirit who is just coming to terms with her own powers could be really engaging.