[1] Shimanaka's education was interrupted by World War II, when he was drafted as mobilized labor and worked Nakajima Aircraft Corporation's research institute.
After graduating from university, Shimanaka joined the staff of his father's magazine Chūō Kōron in 1948,[4] but hoped to pursue an academic career.
[1] Under Shimanaka's guidance, Chūō Kōron was one of the most important magazines of the 1950s and 1960s, publishing both popular and literary fiction by both established and up-and-coming authors as well as opinion-leading thought pieces by scholars and intellectuals.
[6] Japanese right-wing ultranationalist groups were outraged and mounted a long series of protests and attacks aimed at Chūō Kōron in an attempt to force an apology.
"[8] In response, Chūō Kōron's editorial board issued a defiant press release speaking of the magazine's duty to defend freedom of expression, but Shimanaka, deeply shaken by the attack on his household, issued a rebuttal called simply "Apology" (Owabi), in which he repudiated Fukazawa's story as “unsuitable for print," saying it was “published as a result of my own personal negligence.”[9] He then offered his "deepest apologies" for “having disturbed society to the point of causing violent incidents.
"[9] Thereafter, Shimanaka forced the magazine's editor-in-chief to resign,[9] and negotiated a deal with right-wing groups to end the attacks on Chūō Kōron in exchange for a promise to adopt a more "neutral" (i.e. conservative) editorial policy.