ASCII Stick L5 (Japan) (April 1990)
This one-handed controller is being marketed as ideal for RPGs, as you can have one hand free for mapping (and let's face it, JRPGs can easily be played with nothing but a d-pad and a single button. Attack, Attack, Attack, cast heal, Attack, Attack, Attack)
I wonder if they marketed a one-handed controller for the adult visual novel crowd?