- Yoshii's grandfather was a count, so Yoshii inherited the title.
- Yoshii dropped out of Waseda to contribute to Myoujou (Morning Star), the literary journal of Tokyo's Shinshicha (New Poetry Society). 
- Kitahara and Yoshii were dissatisfied with Myoujou's optimistic romanticsm, and gravitated to the elements of dark romanticsm characteristic of European decadent literature.
- They left Myoujou to form Pan no Kai (Society of Pan). This art salon was fashioned after Le Chat Noir in Paris. The members met at a restaurant, which had a picture of the Greek god Pan, to discuss the art and literature of Edo Japan and of France.
- The members of Pan no Kai were also members of Subaru (Pleiades), a literary journal formed in 1909 after Myoujou went out of print. It featured prominent Myoujou poets, and also advocated for romanticsm.
- He was considered a part of the Aesthetic school with Tanizaki Junichirou, following Nagai Kafuu with writings on the pleasure of flesh and love.
- His early poems reflect his nature as a party animal and frequenter of pleasure quarters. He wrote bittersweet poems on melancholic longing, and on the indulgence of alcohol and women. Yoshii published his first poetry collection, Sakehogai (Drunken Ravings), in 1910.
- In addition to being a poet, Yoshii was also a playwright, known for plays such as Yumesuke and the Monk (1910) and Kawachiya Yohei (1911) and thus contributed to the shingeki (new theater) movement. His plays were also published in Subaru. Additionally, Yoshii wrote scripts that were performed on radio in the 1920s.
- Yoshii was a frequent visitor of Kyouka's Bancho house, which was directly across the street from Ton's Arishima Mansion. He wrote a poem about the lantern that Kyouka hung up in tribute to Kouyou.
- Yoshii's poem in Sachio's Birthday Recollection: なつかしき 昔ごころに おもひ出づ 左千夫が描きし 「野菊の墓」を , has a passing mention to Sachio's novella--Nogiku no Haka. However, the association between the two poets is insignificant.
- Yoshii frequented Kyoto's Gion entertainment district, published a poetry collection titled The Songs of Gion (Gion kashu, 1915), and even lived there later in his life. Geiko and maiko lay flowers before a monument for him there on his remembrance day, the Kanikakuni Festival. 
- Dolin, Aleksandr Arkadʹevich. The Fading Golden Age of Japanese Poetry: Tanka and Haiku of the Meiji-Taisho-Showa Period. Akita International University Press, 2015.
- Lippit, Nojiko. Reality and Fiction in Modern Japanese Literature.
- Nakamura Mitsuo. Japanese Fiction in the Taisho Era. Kokusai Bunka Shinkokai (Japan Cultural Society), 1968.
- A Beggar's Art: Scripting Modernity in Japanese Drama, 1900-1930.
- Inouye, Charles. The Similitude of Blossoms: A Critical Biography of Izumi Kyōka