Akis are obvious for fall, but Hina also has some autumnal themes. She's right next to Akis in MoF, and she also has some fallen, orange leaves in pic rel offical art (then again Momiji and Aya also have leaf motives, so I dunno. Many Youkai Mountain denizens seem to be related to autumn in some way, maybe except the Kappa, who are more summer-ish )