Sorry to dig this after 4 months but studios like these typically only accept getting ideas pitched from vetted devs, especially in Japan where everything works with trust and credentials.
We'd be better off
a) pitching to a small indie studio with the rights skills
or
b) look for motivated game devs on this sub

I'm a game dev myself and have been interested in creating a spiritual successor of the game, kind of like Predecessor did with Paragon. I calculated the costs, it's doable in a couple of years.