Hide-and-seek on the bullet train (A Trip To Kyoto) (新幹線かくれんぼの巻) is episode 35 of the Ninja Hattori-kun 1981 anime.
Hattori and the gang are at the train station, seeing Mr and Mrs Mitsuba off. Mrs Mitsuba tells a jealous Kenichi to keep an eye on things while they're away. However, after they've left, Hattori cooks a plan: they take a look at the interior of the train. In the bathrooms, Kenichi washes his face and asks Hattori if he's been on a train before. Hattori says yes, but nothing as luxurious as this. They look at the dining room. Unfortunately, Shinzo needs to go to the bathroom. Kenichi frantically waits for Shinzo to get out of there but the train starts moving. When he does emerge from the loo (by which time the train is already moving), Kenichi furiously shouts at Shinzo, but the gang are interrogated by the conductor, who asks for their tickets. They don't have any, but Hattori gives the conductor money instead, having hidden it around his robes.
Later, in the dining room, the gang are eating, when Kenichi nearly runs into Mr Mitsuba. Hattori makes a distraction by setting a stinkbomb off and the gang make yet another lucky escape.
Now in a town full of old houses, Hattori makes a compliment about the olden days. They do some more sightseeing and Shinzo falls asleep after eating an excessive amount of food. Suddenly, a young journalist finds Hattori and Shinzo. Soon, the whole lot of journalists are swooning over them, while ignoring Kenichi and Shishimaru. Kenichi begs Shishimaru to create a distraction, and Shishimaru sets fireworks off. The gang then scarper.
Back at home, the Mitsubas are watching the news. An item is broadcast about Hattori and Shinzo seen escaping from the flock of journalists. Hattori is extremely taken aback and tries to hide the evidence of what happened.