yeah, sometimes i hope for it too. and i think it did happen at some point, in that time frame when the chapter was spoken by saki-san POV. if i remember right, kuro said that kotoko got injuried dealing with the youkai. so yeah... maybe something that we hoped for did really happen, but the mangaka doesn't want to show us ヽ(`Д´)ノ i mean, what the heck?! there is even a chapter about her in high school before she came in contact with kuro... so... who the hell cares about that?? (surely i don't really care) i srsly wanna see kuro flustered at kotoko sudden disappearance or something like that, yeah! (๑•ㅂ•)و✧
So I just think something crazy immature shit or whatever it is.... Kotoko is my top 10 favorite awesome heroine in this story since i rarely found something who is really intelligent and a real independent character ..so i want kotoko to have some little accident and test how kuro really cares for her... i just want kuro to give even just a little affection to her and i will be really happy which is really rare for me cause sometimes i ship it with other guy(≧∀≦)