I like the concept of Kiku being Ludwig's "first crush" because 1- I am insane but
2- both Japan and Germany were experiencing many changes during this era (in Germany's case the unification + industrialization in Japan's case opening its borders and the whole Meiji era) but they don't necessarily start off as equals. The first treaties the west signed with Japan were quite unfair and though they later were reworked (after a civil war) Japan did still need to modernize immediately if it wished to keep up.
And so it studies what other nations have done and integrates into its own culture and bam 🎉 modernization (<- it's a lot more complicated than this but the basics are there)
I can very much see Gilbert not taking Kiku that seriously at first, not only is there a deep power unbalance between Europe and Asia atp but Japan is a nation that has been isolated for a while + Gilbert just got the massive ego boost of getting the unification to work, forming a proper alliance is just not in his priorities rn though sure he'll entertain the man when their bosses ask them to, on the other hand Kiku is going through lots of new experiences (to say the least) that he mostly dislikes and trying to adapt best as he can so there he is acting nice and probably trying to get some extra information to navigate better the situation -> worth remembering also the japanese did not originally want to sign the treaty with Prussia but the USA mediated the situation and in the end they did
This is all under the shogunato, things change with the Meiji era -> Kiku becomes an active participant in the world stage
Cue in Ludwig who's young (though Kiku meets him properly when he's already physically older) and likely wasn't really there (at least mentally lmao) for the first few meetings as Gil was the one handling everything he makes for the perfect candidate to be a oyatoi gaikokujin of sorts. It's something that can benefit both parties after all: Kiku gets the info he needs and Ludwig can get away from his brother for a tiny little bit proving that he can handle working with other nations hooray 🎉
It's basically when people that want to get into politics have to start by the basics except Ludwig is someone that's very very neglected emotionally at home and gets attached to the one person that actually talks to him instead of at him
(Extra points that realistically Gil and Kiku act alike aisdkdj)
















