Hattori, Shinzo, Shishimaru are looking forward to a trip to the theme park. Unfortunately for them, Mr Mitsuba says that he has some work to do at his office, but promises to make it up to them. Even so, their hearts sink, so Mrs Mitsuba offers to drive them instead. She is initially disheartened when they wear armour, but Hattori reassures her, so after a few hiccups, they set off.
In town, while Mrs Mitsuba, Kenichi, Shinzo and Shishimaru are inside the warm comfort of the car, Hattori sits on the roof. When Kenichi tells her that she's going too slow, Mrs Mitsuba steps on the gas and they shoot off - but all of a sudden, they run out of petrol! Mrs Mitsuba tells the boys to push, so they struggle all the way to the petrol station. Eventually, they refill the car and set off again - but then they lose their way. Kenichi tells her to turn left to go right - not in the same words, of course. Mrs Mitsuba complains that she isn't any good at turning right, resulting in them going in circles. They eventually end up at a farm, where Hattori asks a cow for directions, using Ninja Technique of Animal Language. The cow says that they have to go through the woods to get to the theme park.
As they crash through trees, forcing Hattori to chop them with his sword, they end up on a rickety footbridge. Kenichi is hesitant, but Mrs Mitsuba and Hattori are determined. They cross halfway, but the bridge begins to fall apart, so Hattori guides her the rest of the way. Just as things seem back on track, they reach a dead end. Hattori makes a see-saw, and they rumble at top speed across the way, even flying across a ravine! They eventually reach the theme park, but as it's getting dark, Mrs Mitsuba says they should go home. The gang run off in fright - they've had enough rollercoaster rides for one day!