I posted this link out on Saha's discussion page but it is "awaiting moderation" so I don't even know if it is visible to other people. If you have the paper version of Volume 1 you can see this by taking off the removable cover, it is on the attached outer back cover. I think it foreshadows a WHOLE lot of the plot.
Manga Fox: Kodomo no Jikan Vol.01 Ch.001: Period 1 Online Manga Scans