The present study asserts that the thinking and actions of the politician Tokuma Utsunomiya (1906-2000）is worth taking a look when discussing the Cold War in East Asia, for he worked toward an alternative diplomacy to render the Cold War meaningless in the region. Utsunomiya was a critical figure in the 1973 kidnapping of Kim Tae-jung when South Korea and Japan were in the most strained relations. Furthermore, he acted as a pacifist for disarmament and criticized the mainstream members of the Liberal Democratic Party (LDP), Japan's ruling party to which he belonged himself until 1978. From then, Utsunomiya continuously denounced the party while continuing to work actively as a politician. He fell out with South Korea, chastising the Park Chung-hee administration as well as the Chun Doo-hwan administration after the Kim Tae-jung kidnapping incident and from then attempted to build an amicable relationship with North Korea. Tokuma Utsunomiya was the son of Utsunomiya Taro (1861-1922), the then-commander of the Japanese army in Korea, who cracked down on the March 1st Movement. As son of a military man, Utsunomiya chose a completely different career than his father albeit taking in his Asianist thought. Tokuma became a devout pacifist and negated Japan's alliances with militarist countries such as South Korea and Taiwan and opted for normalization with China and North Korea. Against this backdrop, he stayed the strongest supporter of Kim Tae-jung in Japan, and in the aftermath of the kidnapping had a distinguished role in the movement to spare Kim Tae-jung from imprisonment and death sentence. “Turning to the North to help the South”, he had six meetings with Kim Il-sung to find a way to reconcile with North Korea. The fact that Tokuma Utsunomiya has been recognized as a “conscientious Japanese politician” can be attributed to the absence of an in-depth assessment. As his efforts regarding China and the Korean peninsula are yet to catch much attention and have been always positively appraised, he is being buried in oblivion. With a close look into the significance of Utsunomiya’s actions regarding the Korean peninsula along with a comprehensive evaluation of his political life, this study serves as the first step to delve into his role in diplomatic politics in the post-war era.