Family Colored Neighbors, Vampire Knight, My Girlfriend and Childhood Friend's Grim Shura, Romantic Star Chaser, Stigma of the Wind, Unheard of Flowers

The following barely qualify:

Next Stop Diva, Our Existence, Firefly Forest, Love Song to a Certain Pilot, Memory of a Certain Pilot, Sakamichi's Apollo, Winter Song

This is the first time that I have seen an anime where the main character is a childhood friend.