Sure. There could be fanfics that explore different plotlines with a male reader. For example, the male reader could be a new member of the Night Raid group, and the story could follow his journey of learning the ropes, making friends, and fighting against the corrupt empire. These types of fanfics are more common than hentai ones as they appeal to a wider audience.
For Tatsumi, start with his initial impression in the school. Maybe he's a bit naive at first. As he interacts with Akame more, he could become more confident and assertive. Akame, on the other hand, might start as cold and distant. But as she spends time with Tatsumi, she begins to open up. You can show this through their conversations. For example, Tatsumi might make a joke and Akame might start to smile more often around him.
One idea could be that the OC is a new recruit in Night Raid. Leone takes the OC under her wing, and they gradually develop feelings through training together and going on missions. They could have a moment where they save each other's lives, which deepens their bond.
One popular theme is the male reader joining Night Raid and becoming part of their fight against the empire. Another is the male reader having a special power or weapon that helps in battles.
Akame ga Kill novel's plot is centered around the struggle between Night Raid and the corrupt powers. Night Raid is a group of assassins. Tatsumi's entry into this world of conflict is a significant part of the story. As the story progresses, the battles become more and more fierce. The relationship between different characters, such as the complex feelings between Tatsumi and Esdeath, also adds depth to the overall plot. There are also political intrigues and power struggles within the government that Night Raid is trying to overthrow, which makes the plot very engaging.
The manga of Akame Ga Kill is filled with intense action, complex character developments, and a story of rebellion against a corrupt empire. There are many battles, plot twists, and emotional moments.