Lie
Open your mouth. A tiger fell in there on some spikes! That's what you tell everybody, but when they look in your mouth there's nothing there. It's all a big lie!
Of course there isn't a tiger in your mouth. And those spikes are just normal teeth. No matter how you look at it, you're saying a lie.
None
うそ
None
Lie about spikes in your mouth and I'll put soap with spikes in it in your mouth to teach you a lesson. That's why I'm using uni soap (うそ).
Now at least you're not lying about spikes being in your mouth.