One idea could be a music competition where Miku and Luka are the top contenders. They start off as rivals but as they learn more about each other's music styles and the passion behind them, they become friends and collaborate on a new song. Another plot could involve them traveling through different musical dimensions together, exploring new sounds and rhythms, and using their unique voices to solve the mysteries of these strange musical worlds.
Meiko would be a great addition. She could act as a mentor figure to Miku and Luka, with her more mature and experienced personality in the virtual idol world. Kaito could also be included, perhaps as a friendly rival to both Miku and Luka in music competitions. He could bring a different style of music and a bit of humor to the story.
Definitely fictional. Hatsune Miku is a computer-generated virtual singer and doesn't exist in the physical world. She was designed to entertain and has gained a huge fan following for her unique performances and music.
It depends on the specific fanfiction. There are countless fanfictions out there, each with its own plot and take on the relationship between Yuki and Luka. Some may focus on their friendship and not include a kiss at all, while others might have a more romantic storyline that could involve a kiss.
Hard to say. To determine if Manny is real, one would need to closely examine all the elements and information presented in the Luka Magnotta story. It could be a fictional character or based on a real person with some alterations.