Bouhou Youyoumu

Bouhou Youyoumu is a dungeon exploring action platformer, sequel to Bouhou Koumakyou ~Scarlet Family~, developed by Marokaka.

For reasons presently unknown, Yuyuko throws Youmu down a hole. Why? It's Yuyuko, does she really need a reason? As it turns out though, there really is a constantly-developing story in this game - we just don't understand any of it yet because there's no English patch yet.