Refers to hairpieces used to supplement natural hair, such as switches or extensions. The cross-reference 入れ毛 (いれげ) is a related term.
See also: 入れ毛 (いれげ)
When styling traditional Japanese hair, false hair is used to add volume.
Compound of 入れ (ire, 'inserting') + 髪 (kami, 'hair'), with rendaku voicing of かみ to がみ.