Upon joining Hakuhodo in 1993, Shima started working with the company’s corporate communications department. After being dispatched to the Asahi Shimbun in 2001, he became editorial director of youth-oriented magazine SEVEN, sold at Starbucks and similar locations. From 2002 to 2004, he served as editor-in-chief of Hakuhodo magazine Kokoku. 2004 also saw Shima planning the launch of the Japan Booksellers’ Award, whose executive committee’s board of directors he belongs to this day. In 2006, he founded revolutionary communications company Hakuhodo Kettle, continuing on to serve as editor-in-chief of culture magazine Kettle, local news site Akasaka Keizai Shimbun, and other media content projects. 2012 marked the opening of bookstore B&B in Shimokitazawa, Tokyo, a joint venture with Shintaro Uchinuma. His writings have been compiled in “CHILDLENS” (Littlemore), “Koichiro Shima’s The Way of Making Ideas” (Discover 21), “Kikakuryoku” (“Planning Strength”; Shoeisha), “Kono Tweet wa Oboete Okanakucha.” (“Learn These Tweets”; Kodansha), and “Hito ga Ugoku Mono ga Ureru Henshuujitsu: Brand ‘Media’ no Tsukurikata” (“Creating Things that Move People: How to Make Brand ‘Media’”; Seibundo Shinkosha).