I recently studied japan from 1860 onward, so I think @RustyBrick’s suggestion could be reflective of how in the Meiji period, the Japanese ruling class toured Europe and learned as much as they could about industrial technology, military organization, and the marginally democratic governments of the time. This is reflected in how the Meiji emperor’s dress evolved over time from more traditional garb to a more western military uniform.
Personally, I concur with
@MechatronicJazz that a military bonus would be helpful, and could synergize with the Himeji castle, which is already integral to the HV strategy as japan. Maybe a bonus to building military units that the tech leader(s) have more of than you? I suggested this elsewhere but another idea would be changing the Zaibatsu to replace the Trading Company, maybe have it give a bonus to producing gunpowder units based on number of colonies or something like that?