Who was Tsutomu Yamaguchi, and what is this comic about?

Tsutomu Yamaguchi (1916–2010) was verified through The Guardian, NPR, The New York Times, and HISTORY. The Guardian and NPR confirm his death at 93 in Nagasaki from stomach cancer, his official recognition as the only survivor of both Hiroshima and Nagasaki atomic bombings, and his later advocacy for nuclear abolition. The New York Times confirms the Hiroshima business trip, the return to Nagasaki, and his death in 2010. HISTORY confirms his Mitsubishi Heavy Industries context, double survival, official recognition, and 2010 death. His worth is witness: one injured engineer carried two atomic blasts into a lifelong warning that no city should inherit that sky.

Sources
Page 1 of Tsutomu Yamaguchi: Tsutomu Yamaguchi: Double Light - Yamaguchi begins as an ordinary marine engineer on a Hiroshima business trip.
Yamaguchi begins as an ordinary marine engineer on a Hiroshima business trip.
Page 2 of Tsutomu Yamaguchi: Tsutomu Yamaguchi: Double Light - The Hiroshima bombing burns and wounds him, yet he survives inside the ash.
The Hiroshima bombing burns and wounds him, yet he survives inside the ash.
Page 3 of Tsutomu Yamaguchi: Tsutomu Yamaguchi: Double Light - He travels home to Nagasaki carrying a warning in his body.
He travels home to Nagasaki carrying a warning in his body.
Page 4 of Tsutomu Yamaguchi: Tsutomu Yamaguchi: Double Light - While describing Hiroshima, he survives the second atomic light in Nagasaki.
While describing Hiroshima, he survives the second atomic light in Nagasaki.
Page 5 of Tsutomu Yamaguchi: Tsutomu Yamaguchi: Double Light - He lives through decades of recovery, family, work, and official recognition.
He lives through decades of recovery, family, work, and official recognition.
Page 6 of Tsutomu Yamaguchi: Tsutomu Yamaguchi: Double Light - In old age, he turns memory into testimony against nuclear weapons.
In old age, he turns memory into testimony against nuclear weapons.
Page 7 of Tsutomu Yamaguchi: Tsutomu Yamaguchi: Double Light - He dies in 2010, leaving survival as warning rather than permission.
He dies in 2010, leaving survival as warning rather than permission.
Tsutomu Yamaguchi Obituary Comic - Tsutomu Yamaguchi: Double Light | Memento Mori Obituary Comics