The list with possible suspects is getting longer and longer. We add Ibu to the list! I heard so many names of PoT characters who could be the killer, but I'm glad everybody is thinking about it!
I feel kinda sorry for Tezuka. He had/has to find out everything on his own (okay, with a little help of Yagyuu, Sengoku, Oishi and Ohtori XD).
Don't worry, I can tell you that Eiji will be alright! ^_~