3 girls. One sees the supernatural with her left eye. One writes poems. One is "possessed" by a yamanko. Yamanko is a shortened version of a phrase that means something like: 'mountain god child'. Basically, it means sometimes cute cat ears and tail pop out and her athletic ability gets REALLY good.
Although the 3 girls met by coincidence, they are also classmates.
Taken from MangaFox
Though it was a bit strange, three people ended up meeting. One, who looks younger than her age and able to see the supernatural. Another who is possessed by a "Yamanko" which refers to "Yama no ko", or a mountain child. She was possessed due to her bloodline and due to the possession, she has superhuman abilities which she can call upon. Finally, an awkward person who enjoys writing poems. Coincidentally, the three are also classmates.