I usually use the 13 y/o autistic boy i take care of. because he's autistic he does everything his own way so it's easy to come up with stories.
But i have a second person which is a guitar player friend of a friend who showed me around nagoya when i was lonely in nagoya for a couple days on a 2-week solo travel in tokyo, shizuoka, gifu, osaka, nagoya and kyoto.
and of course i use Mr. T sometimes when i need inspiration from other members' stories on the kanji.koohii site.