The Little Girl in the Bottle

This is the first story. It takes place in the early days of the Honkai War, and follows little Yakumo, Kiana, and Mei as they struggle to survive in Changkong City while searching for a sliver of hope. Along the way, the three meet a silver-haired boy in strange clothes who seems to have come from nowhere, setting them on a journey to find a mysterious girl named Meruko.