Kin’iro Mosaic (2013)

Shinobu Omiya is a 15 year old girl who had once did a homestay in Great Britain when she was 10 years old. She met a blonde, extremely shy, English girl named Alice Cartalet. Once getting to know each other, and getting past the language barrier issue, the two became close friends. On Shinobu’s last day in England, Alice makes a promise that she will come visit Japan someday. 5 years later, Shinobu receives a letter from Alice stating that she is coming to Japan. And on the same day of receiving the letter, Alice appears at Shinobu’s school, revealing that she has transferred to her class and will be staying at her house.

Source: www.anisearch.com/anime/8240