However, I am having a bit of trouble coming up with ideas aside from a few starting pieces regarding Kiba and Toboe, in regards to where they were born in Filgaia, and where their sides of the story begin.

That is, Kiba being from Baskar, while Toboe is an orphan in Meria Boule who's friends with Tony, Scott, and Tim. Tsume might be a bodyguard or hired mercenary, or something other, and I have not a single clue what to do with Hige.