Seirei Gensouki:Spirit Chronicles

Amakawa Haruto was a University student, but years ago he made a promise to his childhood friend, Ayase Miharu that they Get married. Until one day one the highschool entrance ceremony he saw Miharu, buy a day he saw something he didn't want to see and didn't end up talking to her, but then the day after she disappeared witch out a trace. Four years later he's now 21 years old and on a but with two other people. A elementary school girl Endo Suzune and a highschool 3rd year student Matsumato Rikka. But then the bus starts to shake with great force and couldn’t slow down and went on over the train track. At that time a train came down thr track and slam right into the bus, carrying down the track with it. It was such sight an impact that the bus was crush right under the train and no one survived.
Now in the slums of Beltram Kingdom a boy was Suffering from a fever but suddenly woken up with a Amakawa Haruto memory.