Aiha (藍巴, Aiha?) is one of Bishamonten's Shinki. As a Shinki, she takes the form of a medieval suit of armour with a long skirt.
Aiha appears to be a young teenage girl. She is quite short, with a ribbon in her hair. In her human form, she dresses in a smart suit.
Aiha is shown to be jealous of Tsuguha, feeling that Tsuguha had usurped her place as Bishamon's foremost Shin'i (神衣 lit. a god's clothes). Because Bishamonten stopped being close to her shinki and mainly interacted with her battle shinki, Aiha felt worthless as her role as Bishamon's clothing was usurped. She was spiteful and had a short temper. She also gave into temptation, asking Kuguha for advice and being easily manipulated by him into hiding her blight and helping him with his scheme to overthrow Bishamonten. When she realized what was going on, she repented and Bishamonten still kept her despite knowing she became an unwitting pawn in Kuguha's plan. She is deeply loyal to Bishamonten and wanted to do whatever it took to get her attention. She admits, later on, she was wrong and becomes friends with Tsuguha. She is shown to be somewhat of a hypocrite, attacking Yato and thinking him weak but when he fought back and hit her. This action is rebuked by her as he shouldn't hit her because she's a girl and he had no manners, to which he retorted such things didn't matter to a God. She also seems to be a romantic as it is mentioned she likes to tell love stories and when Yato kissed Bishamonten, both she and Tsuguha blushed and she seemed happy. 
Aiha has been Bishamon's Shinki for 50 years. She used to be Bishamon's primary godly clothing, however, was recently replaced by Tsuguha due to Bishamon tripping on Aiha's skirt too much. She cut off Tsuguha's hair out of spite but Tsuguha didn't tattle on her and also talked back to Tsuguha.
Eventually, she began to blight Bishamon and went to Kuguha for assistance. He gave her medicine that hid the blight. Later, he told her if she wanted Bishamonten's attention to use a staff imbued with dark energy to attack Yato while he kidnapped Hiyori. She underestimated Yato and ran, proving to be a good diversion as Kuguha kidnapped both Hiyori and Kazuma.
Aiha asked why Kazuma was captured and why using the staff he gave her caused more blight to spread. Kuguha then calls her stupid and reveals his plans to kill Bishamon and have her replaced, much to Aiha's disgust. He tells her not to worry as he'll be the new guide and forgive her for her sins and won't have to suffer for a master like Bishamon again. As she watches Bishamon and Yato fighting, she cries. Tsuguha sees her and tells her to standby should anything happen to her. Aiha feels increasingly guilty when she hears Bishamon tell Yato she has no traitors among her shinki. Aiha decides to go see Kuraha and leads them to Hiyori and Kazuma, freeing them and apologizing.
Later, she is seen going through an ablution to prevent her from becoming an ayakashi. She manages to make up with everyone and becomes friends with Tsuguha. Aiha accompanied Bishamon as her suit of armor when Bishamon went to Yomi to bring back Yato. When Bishamon fights Izanami, she says her goal is to bring Yato back, and that she has no intention of killing Izanami. Izanami holds Aiha with her hair and captures Kazuma, calling her servants to make Bishamon fall to the ground. Aiha suffered damage to her legs in that battle and was wheelchair-bound for quite some time afterward.
As a shinki, Aiha becomes a full suit of plate armor with a long skirt. She has high defense capabilities, including the usage of Borderlines. As a person, she is quite skilled at needlepoint. In the manga, when she is in her shinki form, the skirt is depicted as red. In the anime, this skirt is depicted as blue.
- The name Aiha means "indigo" (藍) (ai) and "huge comma design" (巴) (ha).
- Noragami Manga: Chapter 22.