I was about to ask a question about Pokemon Tretta in Arqade, but I realized that there is no tag for it.
I was guided to ask here for a tag creation since I'm not yet able to create one.
Ask the question anyway using an as close to approximate tag (in this casepokemon-series would do nicely) and
someone with the privilege will very likely comes across the question and edit in the new tag.
remember that tags need to be used in a question as such can't be created ahead of time and need to be linked to a question (baring recently orphaned tags pending automatic removal)