Awaseru Kao ga Nai " having no face to face someone"

This idiom captures the deep concern japanese have for maintaining face. "Face," of course, means one's positive image, one's public identity and correct behavior wihtin the community. The "having no face" part of the expression can be interpreted as "not knowing what expression to wear," or "not knowing even how to compose one's expression" when having to face someone at a time when one feels deeply ashamed.