Anime Kekkon Yubiwa Monogatari

Satou has been in love with his childhood friend and neighbor, Hime, ever since she and her grandfather appeared out of nowhere 10 years ago. Now a dazzling, yet mysterious high school beauty, she makes it more and more difficult for him to confess his feelings. As the anniversary of their first meeting is nearing, will he muster up his courage to transform their friendship into something more? Or will an entirely different fate await this tightly bonded pair?