This is a quick story using Prompt 2 from this journal [link]
500-1000 words * female character * field trip
This is the same setting as Scene Five [Cousin Sakura] of [link] . Slight cheat in that there's not really a main character, but three out of five human characters present are female so that's something 
When Takeru notices something odd about field trips, it provokes some response... And tempts fate, it seems.