Manatsu Kuroki (黒城舞夏)

Manatsu is a young girl that Ichika met in dreams and a mirror.

Manatsu seems to be the polar opposite of Ichika in terms of personality. When Ichika is hesitant, Manatsu is carefree and assertive; where the former is reserved, the latter is cheerfully outgoing. She also has striking similarities to Ichika, namely, she knows and loves many of the same things Ichika does, and she shares the same fear of ghosts.

(Source: Wikipedia)