Well, 'advance bravely' could be translated in different ways depending on the context. Literally, it is 'advance' which means to move forward, and 'bravely' which means courageously. In a more literary sense in a translation novel, it could be something like 'march forward valiantly' if it's about a military - like scene, or 'proceed fearlessly' if it's about an individual's journey of self - discovery.
One common theme is courage. Just like in the original 'advance bravely', the fanfic often features characters showing great courage in the face of difficulties.
I'm sorry that I can't tell you the plot of the 'advance bravely chai jidan' full novel. There are so many possible themes and storylines it could have. Maybe it's a story of personal growth where the main character, in the context of 'chai jidan' (whatever that might be), faces challenges and learns to be brave and keep advancing. Without reading the novel, it's impossible to accurately describe the plot.
It implies courage and determination. The characters who 'advance bravely' are likely to be facing challenges or difficulties and are not afraid to move forward.
I'm sorry, I haven't heard of a novel named 'advance bravely chai jidan' specifically. There could be many novels out there, and this might be a relatively unknown or a title in a specific genre or region that I'm not familiar with.
Supporting characters are sometimes overlooked in the original but can shine in fanfiction. They can be developed in ways that add depth to the overall story. For example, a sidekick character could be given their own sub - plot that ties into the main story in an unexpected way.
One idea could be to explore the backstories of the characters in more detail. For example, how did they come to be the way they are before the main events of the original story. Another could be to create an alternate universe where the characters have different abilities or relationships.
There could be a 'advance bravely fanfic' that takes the setting of the original work and expands it. Maybe it adds new locations, new cultures, and new rules, making the world even more immersive. It might introduce a new conflict that is related to these new elements, which keeps the readers engaged.