|English voice actor||Andy McAvin|
|Japanese voice actor||Kouji Ishii|
Kimura (Japanese: 木村先生 Kimura-sensei), also known as Mr. Kimura, is the only regular male character in Azumanga Daioh, and teaches classical literature. Kimura openly admits he became a teacher to be close to high-school girls. He is constantly lewd and openly seeks excuses to "observe" girls, such as during swimming class or when they are measured and weighed by the school nurse. He especially likes Kaori, much to her dismay, and has also expressed interest in Kagura, as seen when he asks her how it went after she had got her physicals, possibly also when he sees her and Sakaki in school bathing suits and calls one of the girls "barely legal" or when he, without hesitation, tells Kagura "I like you" in English because she was wearing the gym shorts that he loved. His addressing Kaori by her nickname "Kaorin" is inappropriate for a student-teacher relationship; he takes this a step further by asking her to address him by the similarly cutesy name "Kimurin" ("Mr. Kim-Kims" in the original English manga translation).
Kimura habitually appears with his mouth gaping open (for unknown reasons), and his eyes cannot be seen behind his glasses. At his first appearance in the manga, Kimura seems normal, but takes on his usual expression after he was asked why he became a teacher — as if he had some sort of mental break. In the anime, he is always open-mouthed as well. The one exception is in his family photo. Most female students (and some faculty) intensely loathe him, but many male students admire his "sincerity". He once asked Yukari and Nyamo out for drinks, but they turned him down since they were creeped out by him. He also dressed up as a male high schooler during the 3rd athletic festival, attempting to give Yukari a love letter – since she was dressed up in her old school uniform – and calling her "senpai". This disturbed Yukari. Despite his lewd activities, outside of school Kimura appears as a responsible and kind-hearted person: he recycles littered cans, donates frequently to charities, and even offered ¥10,000 to a shrine as he prayed for world peace. He has a beautiful wife and daughter, who love him despite his strange obsession; his wife even claims to find him very handsome and thinks that "He's cool!"
Kimura at one point drops a photo in the home room, only to have it picked up by the main cast. When Tomo asks who the woman in the picture is, Kimura replies, in heavily accented English: "Mai waifu" ("Mein wife" in the ADV Manga translation). The scene following is one of shock. The girls are unwilling to believe that Kimura could have married such a beautiful woman, and to prove that he is telling the truth, Kimura shows them a family photo of himself, his wife and their daughter (whom the girls are surprised by because she looks smart). The photo is a key part in Kimura's character development as it is one of the only scenes in Azumanga Daioh where Kimura shows any sign of true happiness or any other kind of real emotion.
One notable part of Kimura's character is that he, for unknown reasons, often blurts out phrases in English even though he is speaking to fellow Japanese people, and isn't an English teacher like Yukari. His reasons for doing this are unknown.
Kimura's continued employment at the school in spite of his continued blatant sexual harassment is one of the series' greatest mysteries.
- Kimura first appeared as the protagonist of the comic Azumanga Ohdama by Kiyohiko Azuma from 1999, along with characters such as Osaka, Tadakichi-san, Chiyo, Yomi, Sakaki and Kaorin. In this comic, he is unnamed.
- Kimura's line "Mai Waifu (an Engrish of "My Wife") has become a common term by fans to describe anime or video game women that are, in their opinion, "desirable".