Table of Contents
The current mainstream Sehto culture was seeded with Johto settlers starting in 1400 and subtly 'corrupted' by the Xhosa's African influences and the isolation of the island, ultimately budding in its own distinct culture that's continued its evolution ever since.
Politics and Ethics
Like in Kanto and Johto, Sehto is largely anarchic, with the towns autonomous and the closest thing to authority figures coming in the form of the pokémon gymleaders in the towns that have them. The Sehto code of conduct amongst strangers is a rather minimalistic consent-based creed: Anything lucidly agreed on is fair and can and should be enforced, potentially by third parties. Naturally there are deviations with how far anyone takes that on personal levels, and Taqnateh's gym battle rules would strike a negative chord with many, but the ethical attitude is prominent. Its effect is further worsened by a strong territorial respect - the rules of anyone's home are to be respected.
Murder, theft and vandalism are of course not okay, reducing to the consent axiom. For various other things, implicit consent can be assumed at risk of all involvees. Arbitration on Sehto is roughly akin to the principle of Xeer, albeit separately constructed.
Only Nightclaw, Vale and Njoty have something like public police forces. With no government overseeing the entire island, there are no taxes to fund them - they're run partly as charities, partly voluntarily, and partly by being paid by larger companies who have an interest in keeping the city they trade in safe from the grip of chaos, though latter is viewed with suspicion.
Customs
Sehtoan customs are fairly Western, all things considered. It's expected one respects strangers until they prove themselves not worthy of respect, i.e. there's a societal pressure to be polite, but there is no social pressure to be, well… social. (Togi is an example of Sehtoan 'extremists' gently isolating themselves from the rest of Sehto to champion the kind of individuality that the overarching culture permits.) The culture is unabashedly egalitarian - no one cares about biological circumstances. That's to a fault - no one in Sehto will let anyone let 'hormonal disabilities' count as a valid excuse to deviate from acceptable behaviour, for example, since it's expected you act acceptably regardless of your predisposition.
Economy
Sehto's towns largely attempt to be self-sufficient, with Togi and Taqnateh the most notable exceptions, former which refuses to integrate with the rest of Sehto for anything but commerce, latter which might as well consider itself part of Vale.
Imports and exports chiefly go through Ehqaj City. Economic power in Sehto is roughly equivalent to the size of the settlements - Nightclaw is the productive powerhouse of the whole island, and trade flows from there into other towns and back out.