Lily Clairet, Vol. 1

A young girl is arguing with a cherry tree. That's a new one for Lily, who's managed to reach the end of her first year at high school without too much weirdness. Unfortunately for her, it's not long after solving this odd mystery that her untroubled life begins to unravel. Discovering an abandoned room at the end of the music department corridor, she finds that aside from it being utterly run-down, it's also devoid of its sole occupant:

Sonata Sonoda, the missing journalism club president.