Foe Yay: Onibi really likes Hibana. All the cutscenes with him involve him putting the moves on her. It's one-sided, as after Hibana kills Onibi, she says 'Damn... now I just feel dirty.'
Fridge Brilliance: Of course Hisui has the slowest attack speed, because her weapon is a giant umbrella!
Fridge Logic: You are in a quest to, among other things, collect the various pieces of the cursed sword Akujiki. The first cutscene with Onibi in level 5 shows that the purple containers that recharge your special attack ingame actually contain about 3-inch-long shards of the cursed sword. You collect somewhere around a dozen. Per level. Just how Goddamn big is it?
That One Level: Golden Palace. Hibana can double-jump and air-dash once each before needing to land, unless she manages to kill an enemy in mid-air. Golden Palace is the first level where this is required to navigate across a bottomless pit, which demands quick reflexes and pinpoint accuracy. This ends up presenting the game's primary Scrappy Mechanic: "Tate pits" will likely be the players' main source of game overs, as tate chains have a tendency to randomly end halfway through the run of enemies.