Landlady of Narutaki Sou. She attends the same high school as Tamami. She has several different personalities that come out when she experiences different emotions, but returns to her original one after sleeping or passing out. Each of her different personalities has a different hairstyle involving the bells she ties her hair up in and each personality has a different eye color. Kozue's eye color is a bluish green. Ryūshi is her second cousin. She is extremely nice and like all of her personalities, she enjoys umeboshi. In the manga, she begins a relationship with Ryūshi from chapter 39. In the epilogue, it seems that she is married to Ryūshi, having four kids, most likely representing her other personalities. At the start of the series, she is sixteen years old and her birthday is on December 22.
Other personalities:
Saki Akasaka
Saki, whose eyes are red, has a very tough attitude and wears her hair with a pony tail in back. Despite this, she actually does care about others, even if she is embarrassed to admit it. She appears when Kozue is surprised or angered. She is an extreme lightweight, and unable to tolerate anything but umeshu (in the manga), in the anime she can't even smell liquor without passing out. Her other weakness is fear of butterflies.
Nanako Kanazawa
Nanako has the personality of a 6 year old. Her hairstyle contains two "antennae". She has yellow eyes. She appears when Kozue is embarrassed.She is usually better behaved after she becomes "Shiny." One other noteworthy feature of Nanako is that of all the other personalities that Kozue goes through, Nanako is the only one given an actual age. According to the manga, Saki, Chiyuri, and Natsume all are of unknown age, though it is safe to assume that all of the others have the same age as Kozue.
Chiyuri Midorikawa
Chiyuri loves cosplay. She also makes everyone else cosplay against their will, but only if it is against their will. If they don't care or want her to do so, she won't want to. She appears when Kozue is clumsy or frightened. She wears a large pony tail to the side and has green eyes. While she is in this personality, Tamami acts as her assistant, whom Chiyuri refers to as "my partner," while supplying Tamami many embarrassing photo-ops with which to fill her camera. Tamami, in return, calls Chiyuri "my sweetheart". "Correct!" is her catch phrase.
Natsume Konno
Natsume has a very shy personality who initially avoided speaking to anyone at all. She is extremely skilled at sleight of hand and card tricks. The first time she talked was when teaching Ryushi one. Flowers will spontaneously pop out of the top of her head (a parody of the first magic trick she shows Ryushi) when she's happy. Her hairstyle is high pigtails with a layer of hair in the back. She has blue eyes. She has a habit of ending her sentences with "... kamo," meaning either "maybe" or "I think" depending on the context. She appears when Kozue is saddened.