One idea could be exploring the backstories of the characters in more depth. For example, delving into the past experiences that made them who they are in the Dakaichi world.
Begin by choosing a character you want to focus on in your fanfiction. It could be the main character or a side character that you find interesting. Research their traits and quirks from the show. After that, start writing short scenes or dialogues that are in line with their personalities. For instance, if the character is known for being shy, write a scene where they have to overcome their shyness in a new situation.
You could check out 'Slam Dunk'. It's known for its exciting story and strong basketball-playing boys. The characters have unique skills and personalities that make it very engaging.
Alan Grant's comics are known for their unexpected plot twists and a good balance between action and character-driven moments. The dialogues are often sharp and engaging too.
It might suggest a sense of loss or sadness related to the departure of the cartoon dog. Or it could be a symbolic statement for something else, like saying goodbye to a childhood memory associated with the dog.
They have different personalities and powers. Batman is a human with no superpowers but is highly intelligent and skilled. Superman has superhuman powers. But they both fight for justice and protect the innocent.