I have already decided that if I do this, it will start with a converted Keep on the Shadowfell. As I have not read further than a few pages into the Keep, all of the following is conjecture:
The Keep is Shiro Hiruma/a fallen Crab outpost/a Shadowlands outpost that the players are sent to investigate. Patrols are a normal duty of those along the wall so even a fresh batch of recruits is expected to take part in the forays.
All of the kobolds and other creatures will be changed to oni and ogres and bakemono. The characters are Crabs and maybe a few samurai from other clans with obvious ties to the Crab. A Hida Bushi (dwarf fighter) is an automatic include no matter what. I could make all the characters Crab with ease, utilizing two Hida Bushi (dwarf fighter and dwarf warlord), a Kaiu Engineer (tactical warlord or artificer), a Hiruma Scout (rogue), and a Kuni Shugenja (wizard with cleric multiclass). Or I can go whole-hog with the clans and use the characters I have already created (Hida Bushi, Mirumoto Bushi, Isawa Shugenja, Togashi Ise Zumi, Shosuro Shinobi, Moto Bushi, Kakita Kenshinzen, etc).
Further adventures call for an encounter with Spider Clan samurai (before they were the Spider Clan). These Lost would call themselves by the name Daigotsu, such as Daigotsu Tsuno. They would be analogous to the Dark Warlords from Ronin Warriors.
Also, all of the armor special attacks from Ronin Warriors can and will be written up as powers. I just need to find something appropriate to model them on (i.e. choose a good level to house the effect).