"Oh, c´mon... I hate being seen by human whippersnappers. Now you want me to actually look at you? To TALK to you? I don't think I could stand it, sonny. Well, go on then, let´s get this battle over with. I want to get back to the John. The fate of the world´s important, sure, but don´t discount the toilet. It´s a little world in itself."
"The Japanese god of the toilet, his full name is Kanbari Nyudo. He keeps the toilets worry-free, and if you recite the words "Kanbari Nyudo hototogisu" in the toilet on New Year's Eve, you won't have to worry about seeing monsters in the toilet for the next year. Old toilets were not only simple, but also constructed dangerously, so Kanbari is thought to originate in fears of the toilets."
—Shin Megami Tensei: Strange Journey Compendium
He appears as a miniboss in an EX Mission, Lurker of the toilets. Aboard the Red Sprite's bathrooms, several crew members will have noted the strange presence of the demon; the protagonist was sent in to deal with him; when defeated, he chided the crew for sloppy maintenance of the bathrooms. Afterwards, the crew agreed to maintain a regular bathroom cleaning schedule... after reminding the protagonist to wash his hands.
He as well can be found in Sector Carina with the enemy search app.