Double x Cross  

ダブル×クロス

Natsumi attends high school with her childhood friend, Haruyuki. However, he has been treating her coldly and formally. One morning, she wakes up to find that a miniature version of Haruyuki is in her room. No one else can see or hear the tiny Haruyuki, and when Natsumi goes to school, she finds that the original Haruyuki still exists. What is the source of the miniature Haruyuki, and how can he be reunited with his full-sized counterpart?