Ringo Uri no Utakata Shoujo

Synopsis

What would you give up for a chance at eternal life? Money? Friendship? Memories? Most people would consider it, if not actually go through with it. After all, immortality gives you an endless amount of possibilities... And yet this story tells a tale of a boy who considers to give up his immortality for just one thing — the friendship of a stranger... (Source: Vocalations)