How old is Serizawa?

Question

In 2014's Godzilla, this scene occurs:

Admiral William Stenz: [on mobilizing warheads] I know you don't agree with this. But my first priority is to safeguard our citizens.

[Serizawa shows Admiral Stenz a watch]

Admiral William Stenz: It's stopped.

Dr. Ichiro Serizawa: Yes. Eight-fifteen in the morning, August 6 1945.

Admiral William Stenz: Hiroshima.

Dr. Ichiro Serizawa: It was my father's.

It may not come across clearly in the transcript, but to me at least, the scene highly implied that Serizawa's father died in the atomic bombing.

However, if that was true, it would make Serizawa about 70 years old, minimum. He doesn't appear to be that old. His actor, Ken Watanabe was only born in 1959.

So was Serizawa born during or before WWII, or did I totally misread the scene?

Answer 1

Contradictory evidence

The official novelization describes Ishiro Serizawa as being in his early forties, as mentioned in Valorum's answer.

On the other hand, the equally official prequel comic Godzilla: Awakening shows Ishiro's father finding him in the aftermath of the Hiroshima bombing.

This is more consistent with the implication in the film that the watch belonged to Serizawa's father (who was indeed caught in the blast, but survived), but less so with his actor's apparent age.

Answer 2

The film's Official Novelisation describes him as being in his early 40s in the year 1999. Presumably then, his father didn't die at Hiroshima but was sufficiently close that his watch stopped working.

1999

Dr. Ishiro Serizawa gazed out the side door of the helicopter as it soared over a lush green landscape. Below him stretched a sunlit tropical rain forest clinging to the rugged slopes of the Philippine highlands. Pines and other evergreens dominated the pristine mountainsides, while mahogany and bamboo groves thrived at the lower altitudes, painting a scenic portrait of pure, unsullied nature. A distinguished-looking man in his early forties, with receding black hair and a neatly trimmed mustache and beard, Serizawa enjoyed the view—until he spied his destination.