Ashita no 3600-byou

Synopsis

May of their second year in high school. On the final day of their field trip! Natsuho just can't help but be concerned about a boy named Kayano in the same group as her and his lone wolf behavior. During their trip, she happens upon a dilapidated small shrine, which she can't help but clean up and make an offering to. That's when strange things start happening to her... What is possibly the greatest love in history has begun! (Source: Clairparfait)