This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages) The topic of this article may not meet Wikipedia's notability guideline for biographies. Please help to demonstrate the notability of the topic by citing reliable secondary sources that are independent of the topic and provide significant coverage of it beyond a mere trivial mention. If notability cannot be shown, the article is likely to be merged, redirected, or deleted.Find sources: "Jidayu Koizumi" – news · newspapers · books · scholar · JSTOR (March 2014) (Learn how and when to remove this template message) This article does not cite any sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.Find sources: "Jidayu Koizumi" – news · newspapers · books · scholar · JSTOR (March 2014) (Learn how and when to remove this template message) .mw-parser-output .hidden-begin{box-sizing:border-box;width:100%;padding:5px;border:none;font-size:95%}.mw-parser-output .hidden-title{font-weight:bold;line-height:1.6;text-align:left}.mw-parser-output .hidden-content{text-align:left}@media all and (max-width:500px){.mw-parser-output .hidden-begin{width:auto!important;clear:none!important;float:none!important))You can help expand this article with text translated from the corresponding article in Japanese. (March 2014) Click [show] for important translation instructions. View a machine-translated version of the Japanese article. Machine translation, like DeepL or Google Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Consider adding a topic to this template: there are already 3,804 articles in the main category, and specifying|topic= will aid in categorization. Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article. You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation. A model attribution edit summary is Content in this edit is translated from the existing Japanese Wikipedia article at [[:ja:ja:小泉次大夫]]; see its history for attribution. You should also add the template ((Translated|ja|ja:小泉次大夫)) to the talk page. For more guidance, see Wikipedia:Translation. (Learn how and when to remove this template message)