Additional cast from the latest Monthly Asuka.
Saitou Yakumo: Ono Daisuke
Ozawa Haruka: Fujimura Ayumi (Drama CD: Hirano Aya)
Gotou Kazutoshi: Touchi Hiroki
Saitou Isshin: Seki Toshihiko (Drama CD: Narita Ken)
Ishii Yuutarou: Kawashima Tokuyoshi
Hata Hideyoshi: Naya Rokurou
Hijikata Makoto: Toyoguchi Megumi
Saitou Unkai: Takase Akimitsu
Nanase Miyuki: Yuzuki Ryouka
That last name is surprising, because...
Spoiler for Novel adaption episode guesses:
From what I understand Nanase Miyuki is a character from book 4.
Assuming that they're going with Oda's manga for the anime... there will only be the Locked Room story from the first book, which should take no more than one or two episodes depending on the pace.
Then 5 or 6 eps for each of the remaining books.
