A shutline fan account (@/jaketookthemoon on Twitter translated all of the authors q&as and someone had asked her if Jake was Russian-American but only replied that he wasn't American So she didn't deny the Russian part so it's possible he might be but we won't know until the new season comes out.
There are no spoilers, this is an original, it has no novel and the chapters put here are up to date, the only thing to do is wait, the creator is kind of slow in creating the chapters unfortunatelly
I feel bad for her omgg(〜 ̄△ ̄)〜