The three-wheeled vehicle, developed by Japanese toilet maker Toto, features a toilet for a seat and has a giant roll of toilet paper mounted on the back that flutters in the breeze as the bike cruises along.
But there are no plans to put the bike on sale. Toto intends to put it on display.
The biogas used as fuel for the Neo is produced from a combination of household sewage and livestock waste, broken down and fermented, company spokesman Kenji Fujita said.
"Although the seat of the bike is indeed a toilet, it is not for actual use. The fuel is eco-friendly biogas, stored in the tanks on the back," he said.
"It's a surprisingly nice way to travel."
The 380 kg (837 lb) motorcycle can run for a total of 300 km and reach speeds of up to 70 km an hour (45 mph).
Ichie Tanaka, one of six people who rode the Neo across Japan during the three-week, 1,400 km (870 miles) tour to promote biofuels, said she was relieved the journey was over.
"At first when I saw the bike, I was taken aback. But after riding it, I found it quite interesting," the 28-year-old said.
"It doesn't hurt at all and is actually quite comfortable to sit on."