Yuuichi learns later on that Mai had healing powers ever since she was little which helped heal her mother when she was about to die. However, this power was feared by the townspeople and forced Mai and her mother to move. Soon after moving to a new town she was told she will meet someone who can understand her powers and become a great friend, and that friend was Yuuichi.
However, this relationship had to end as Yuuichi had to leave the town and go back home. This caused Mai grief, and in her desperation she began making up a story about monsters invading their favorite place to play together: a field of wheat which became the school they go to in the present day. These monsters became real due to her very own powers.