Yosano was born into a prosperous merchant family in Sakai, near Osaka. From the age of 11, she was the family member most responsible for running the family business, which produced and sold youkan, a type of confection. From early childhood, she was fond of reading literary works, and read widely in her father's extensive library. As a high school student, she began to subscribe to the poetry magazine Myōjō (Bright Star), of which she became a prominent contributor. Myōjō's editor, Tekkan Yosano, taught her tanka poetry, having met her on visits to Osaka and Sakai to deliver lectures and teach in workshops.
Although Tekkan had a common-law wife, he and Akiko fell in love, and he eventually separated from his common-law wife. The two poets started a new life together in the suburb of Tokyo and were married in 1901. The couple had two sons, Hikaru and Shigeru. Despite separating from his first wife, Tekkan remained actively involved with her.
In 1901, Yosano brought out her first volume of tanka, Midaregami (Tangled Hair), which contained 400 poems and was mostly denounced by literary critics. Despite this critical reaction, it was widely read and became a sort of lighthouse for free-thinkers of her time. Her first book, by far her best known, brought a passionate individualism to traditional tanka poetry, unlike any other work of the late Meiji period.
The Midaregami is Akiko Yosano’s first collection of tanka (31 syllable poems, arranged in 5-7-5-7-7), published in 1901 and consisting of around 400 poems. The majority are love poems through which Akiko expresses her feelings towards Tekkan Yosano. It was through this particular collection that she set an image for herself as well as the stage for female voices in modern Japan. The poems tended to express femininity in a manner unconventional for her time, especially from a female writer.
In traditional Japanese values, women are perceived as (and are expected to be) gentle and modest. The domestic and societal roles of Japanese women were and are focused on procreation and raising children, especially boys. Midaregami not only expresses concepts and/or issues that pertain to women and are not normally voiced in such a public manner, but also created a new, revolutionary image of womanhood, as lively, free, sexual and assertive people, nothing at all like the conventional picture of the modest, demure young lady expected in Japan. Yosano's women were not passive, but active agents of their love lives. The Midaregami posed a challenge to patriarchal values of Japanese society, as well as the accepted literary and cultural conventions of her time. Although Akiko Yosano’s work was denounced and severely criticized, it served as a great source of inspiration to women of her day. The visual representations of flesh, lips and breasts symbolize women’s sexuality. No poet had written of breasts in a tanka before, which led the poet Nobutsuna Sasaki to attack her in a magazine article for "corrupting public morals" and "mouthing obscenities fit for a whore". From the examples in the Midaregami, the idea of nudity changed the way Japanese people viewed eroticism and female sexuality. Up until this point women’s breasts were a symbol for child feeding and motherhood. From then on they began to take on a different representation; that of natural beauty, and especially that of young women. A door was opened for Japanese women to imagine new representations of sexuality and the female body.
She followed this with twenty more tanka anthologies over the course of her career, including Koigoromo (Robe of Love) and Maihime (Dancer). Her husband Tekkan was also a poet, but his reputation was eclipsed by hers. He continued to publish his wife's work and to encourage her in her literary career. Yosano Akiko was an extraordinarily prolific writer. She could produce as many as 50 poems in one sitting. During the course of her lifetime, Yosano Akiko is thought to have written between 20,000 to 50,000 poems. She also wrote 11 books of prose.
Yosano helped to found what was originally a girls' school, the Bunka Gakuin (Institute of Culture), together with Nishimura Isaku, Kawasaki Natsu and others, and became its first dean and chief lecturer. She assisted many aspiring writers to gain a foothold in the literary world. She was a lifelong advocate of women's education. She also translated the Japanese classics into modern Japanese, including the Shinyaku Genji Monogatari (Newly Translated Tale of Genji) and Shinyaku Eiga Monogatari (Newly Translated Tale of Flowering Fortunes).
Yosano's poem Kimi Shinitamou koto nakare (君死にたもうこと勿れ, Thou Shalt Not Die), addressed to her younger brother, was published in Myōjō during the height of the Russo-Japanese War and was extremely controversial. Made into a song, it was used as a mild form of anti-war protest, as the number of Japanese casualties from the bloody Siege of Port Arthur became public. In September 1904, Yosano had learned that Japanese soldiers at Port Arthur were being used as "human bullets", being strapped with explosives and sent to blast holes through the Russian barbed wire entanglements in suicide missions. Yosano's younger brother serving in the Imperial Army and was attached to the forces besieging Port Arthur. In Bushido, it was the highest honor for a man to die for the Emperor, and knowing of her brother's impulsive nature, Yosano was seized with the fear that he might volunteer to be a "human bullet", inspiring her to write a poem pledging with him to think of his widowed mother. Addressed to her brother, Yosano wrote: "Did our parents make you grasp the sword and teach you to kill? For you what does it matter whether the fortress of Lüshun [Port Arthur] falls or not?" Yosano attacked the central concept of Bushido in the Kimi, noting that it was the greatest honor for a man to die for the Emperor, whom she sarcastically noted never put himself in harm's way, expecting others to die for him. For calling the war with Russia senseless and stupid Yosano made herself into Japan's most controversial poet, and the government attempted to ban her poem. The Kimi was so unpopular that Yosano's house was stoned by angry people while she became involved in a rancorous debate with the journalist Omachi Keigestu over the question of whether poets had the duty to support the war or not.
The first issue of the liberal journal Seito in September 1911 featured her poem "The Day the Mountains Move" asking for woman to be given equal rights.. In a 1918 article, Yosano attacked "the ruling and military class which deliberately block the adoption of a truly moral system in an effort to protect the wealth and influence of their families...They hurry to invoke the power and precepts of the old totalitarian moral codes to direct the lives of Japanese citizens". Yosano ended her article by calling militarism a form of "barbarian thinking which is the responsibility of us women to eradicate from our mist".
Yosano gave birth to 13 children, of whom 11 survived to adulthood. The Japanese politician Yosano Kaoru is one of her grandsons.
During the Taishō period, Yosano turned her attention to social commentary, with Hito oyobi Onna to shite (As a Human and as a Woman), Gekido no Naka o Iku (Going through Turbulent Times) and her autobiography Akarumi e (To the Light). In 1931, Yosano, Japan's most famous pacifist succumbed to the "war fever" that gripped Japan when the Kwantung Army seized Manchuria. In a poem from 1932, "Rosy-Cheeked Death" concerning the First Battle of Shanghai, Yosano supported her country against China, through she also portrayed the Chinese soldiers killed in the battle as victims, albeit only of Chiang Kai-shek, who she accused of betraying the legacy of Dr. Sun Yet-sen, who always preached Sino-Japanese friendship. In "Rosy-Cheeked Death", the Chinese are "foolish" to resist Japan because Japan is a "good neighbor" whom they could never hope to defeat, making their resistance futile. In her poem "Citizens of Japan, A Morning Song" published in June 1932, Yosano embraced Bushido as she praised a Japanese soldier for dying for the Emperor at the First Battle of Shanghai as she described how the soldier "scatters" his body when he is blown apart as a "human bomb". Yosnao called the "scattered" body of the soldier "purer than a flower, giving life to a samurai's honor". Unlike the Kimi, Yosano called for Japanese women to "unify in loyalty" for the "cause of the Emperor's forces". The American scholar Steven Robson noted that unlike the Kimi, which like the rest of Yosano's early poetry was extremely innovative, Citizens of Japan is cliche-ridden as Yosano used well-known phrases like "a samurai's honor" taken straight from the ultra-nationalist press without developing a vocabulary of her own. Yosano ended her poem by praising Bushido, declaring that the "purest" act a Japanese man could perform was to die for the Emperor in battle and urged the Kwantung Army forward onward in the conquest of Manchuria "through suffering a hundredfold" to "smash the sissified dreams of compromise".
Yosano's poems from 1937 onward support the war against China, and in 1941, she supported war against the United States and the United Kingdom. Her late commentaries in the early Showa years tended to praise militarism, and also promoted her feminist viewpoints. Her final work, Shin Man'yōshū (New Man'yōshū, 1937–39) was a compilation of 26,783 poems by 6,675 contributors, written over a 60-year period.
In 1942, in one of her last poems, Yosano praised her son who was serving as a lieutenant the Imperial Navy, urging him to "fight bravely" for the Emperor in "this sacred war". Yosano died of a stroke in 1942 at the age of 63. Her death, occurring in the middle of the Pacific War, went almost unnoticed in the press, and after the end of the war, her works were largely forgotten by critics and the public. In the 1950s, the Kimi was made mandatory reading in Japanese high schools, and during the protests led by idealistic university students against the government of Nobusuke Kishi, whose intention was to do away with Article 9 of the constitution, the Kimi become something of an anthem for the students. Her romantic, sensual style has come back into popularity in recent years, and she has an ever-increasing following. Her grave is at Tama Cemetery in Fuchu, Tokyo.