There are three manga series that revolve around those characters (Yato and Hisako). The first is Kindan No Koi Wo Shiyou, the second is Zoki - Kindan no Koi Wo Shiyou, and the third (which is the longest in the collection of books) Kindan no Koi de Ikou.
"Tomesode and obi - the nape of a woman's neck is considered very sensual and beautiful in the Japanese culture. Kimonos are designed to draw attention to the neck with upswept hair. Noted for costume design.