Oh, woh... they can't have that, can they? Shoto's mildly surprised at worst. He'll still try to prevent possession—though with growing concern for his mentor and not through any actual fault of the ghosts. He'll calmly promise he'll come back (with far better gifts than the sweets he's left), but he is absolutely bargaining—promising plenty of things in earnest (and clearly despite his teacher's wishes), asking the spirit to leave them be, but in exchange for something better. He needs to see what's beyond that mist! He can't let Hijikata spiral, though...!

He'd really like to return alone! But Hijikata comes first right now!