Secrets & Special Skills
The past of your main character is essential. You won't necessarily have to divulge every bit of it. You might not even want to shed any light on your character's past at all.
What I usually do is write down every single major event that had happened and draw some of these events to create a set a special skills.
How to create these special skills?
What happens in your childhood moulds you in the future, whether we like it or not. This is something crucial you can do with your character/s, too.
Consider the following example:
Your character has been left by her mother and/or her father. She is deeply wounded by this and will react different ways as she's getting older:
- She will stand out for friends and the rest of her family and tries to keep everyone together. She will develop a savior complex and will think it's her duty to save people from themselves.
- She will think that everyone is capable of leaving her and will have strong trust issues towards everyone who is close to her. As a result, she will be pushed away by people who actually like/love her and she'll find herself alone.
Her special skills in the first scenario is her capacity to pinpoint problems and find a resolution as quickly as possible. From her skills, you can draw the Fatal Flaw.
The secret of her parents leaving her is consuming her. She will not share that secret, and if she does, it's going to be a big deal. The secret sets off a course of action and her own set of skills. These two are intimately intricated. And you will be able to draw much more from her past.
You can create a very strong contrast from the person your character was as a young girl to the person your character becomes as a teenager.
Childhood tends to be a period of time when you're full of hope and nothing can stop from doing whatever you want. From there, you can create a character development from hope to despair, from innocence to guilt - and those are only the most frequent patterns used.
Even if these patterns have been used and re-used so many times, you can still make the most of it. Don't forget that the story could have been told many, many times, but your storyline is going to be unique and reflects your talents as a mangaka.
You don't necessarily have to show any parts of the childhood in your manga. You can have other characters describing or explaining the past events.
But I would recommend to actually show what has happened. Lengthy explanations and descriptions could become bothersome to your fans and readers.
Manga is mostly a visual media, so showing instead of telling is sometimes better.
But don't take it as a rule: your manga, your rules.