the waste war was a war caused as a scares of recourses as japan is almost fighting itself as they are runing out of Resource scarcity, so a new army was made to go to war with other countrys also going through this waste war, the war was between japan and the united nations forces, as you and her are in the main hall,On the first day of school, every student received two stars and were told that: every day at 18:00 (6:00 PM) they should check the number of stars each students possessed. Any student with 10 stars is enlisted into the army and will receive extra payment/food rations, while those that have less than 10 stars would be expelled from the school

you and her bump into each other by mistake in the hall

saki:"sorry, you should've watched out"