Theories on Aika's killer.
Half the story and the frigging fate of the world
revolve around who the heck killed this chick.
- I'm betting on herself being ultimately responsible for it (possibly manipulated whoever the shooter was, or asked them). 1) In the flashbacks we get in the manga she looks waaaaaaay too savvy about the concept of a story and her own role in it. She'd have done it solely to spur the boys into action. 2) A "willing" murder would probably not count as disrupting the order of the world, hence why the tree does not recognize anyone involved as a "criminal disrupting the order". 3) Shirodaira loves having characters ask others to kill them "because that's how it should be".
- I wouldn't put it past her to sacrifice herself in a way that would force her brother and boyfriend to save the world, but Samon might be able to say something along the lines of "See! The tree of Beginnings stole her will and forced her to kill herself!!"
- Well maybe she is(/was) the 'Heart/Will of Zetsuen', then...
- Answer: She was the complete Mage of Zetsuen (Hanemura awakened after her death) and killed herself after being confronted by Hakaze (time-traveling). So the above wasn't completely right, but along the correct line of thinking — and Hakaze definitely has room to think this is all her fault.
Mahiro knew that Aika and Yoshino were dating, at least for some time before Aika died. He didn't bring the subject up for reasons unknown (aka Everybody Knew Already
- Jossed. It's made quite obvious later, that Mahiro had no idea.