Its a bit hard to explain. The secret of Onomichi is not really that they have a working battleship
that they want to use or whatever. The ship as a object or machine is worthless now.
The secret of Onomichi, the battleship, is more of a symbol that shouldnt exist.
It was a super modern ship back in the day and designed to be the best of the best but WW2 ended
before they could use it. After the war, Japan was not allowed
to have any military, especially not a brand new battleship, so the responsible people concealed it.
So if the world would find out that the japanese had a brand new working battleship
that was completed and ready after WW2, this would be one of the biggest scandals ever.
Minoru Daidoji (the super old guy in the bed) ordered this ship in WW2 because he refused to accept to surrender.
(he was a admiral back then)
The ship was built by chinese migrants that were smuggled into the country by the chinese triads
on behalf of Heizo Iwami (the owner of the japanese shipbuilding company)
Also huge amounts of illegally obtained public funds were needed to execute the project.
(which the japanese military supported back then)
Then Daidoji learned that the battleship wouldnt be enough to stop the americans,
which is why he ordered Heizo Iwami (the other older guy with the beard)
to destroy it. But he didnt.
Instead he started blackmailing Minoru Daidoji and he had no other choice than accepting it.
In return of Daidojis support he was now responsible to hide the secret of Onomichi forever.
After the war ended, Daidoji was seen as a war hero which gained him a career in politics
and he became one of the leaders of Japan.
But all of this, Daidojis status, Iwamis position as chairman, the power of the Yomei and so on
is kind of built on this secret. Also the huge amounts of wasted illegaly obtained money,
chinese migrant workers, the secret supported by the japanese military, corrupt politicians ...
Its a very big and deep network that is built on this secret or on people that are involved in the whole thing
and you also have to remember this whole japanese honor thing.
Its not just the money, migrants, war agreement scandal,
it would also bring huge huge huge shame upon the modern country of Japan
and it would reveal this whole network of illegal activities.
The secret of Onomichi is not that the japanese want to start a new war with one old ship.
Its about the meaning of the ship.
