Kuromori-san wa Smartphone ga Tsukaenai

When Suzuki Oji enrolled into high-school, he was hoping for some kind of excitement to occur in his life but he never expected it to take the form of Kuromori Kisaki, a descendant from a 400 year old clan of witches. However, Kuromori needs a special brooch in order to fly on her broom, something she lost when she landed on Suzuki after he had mistakenly thought she was falling to her death. Although he initially thinks Kuromori is being unfairly difficult to socialize with due to her "witch" status, he finds and returns the brooch to her who out of gratitude, shows her flying magic to him. Suzuki then questions the possibility of himself flying by also wearing the brooch, but right after Kuromori pins it to his coat, both of them suddenly find themselves several feet in the air before falling into the school's swimming pool. So just who or what is Suzuki...?