Let's make a raft with empty cans (あきカンでイカダを作るの巻) is episode 137 of the 1981 anime.

Upon seeing Kemumaki's raft made out of logs, Hattori and the gang make a raft for themselves - made out of empty

The gang work on their raft, oblivious to Kemumaki's plans...



Kemumaki and Kagechiyo are proudly sailing their raft made of logs around the river taunting Hattori. Kenichi tells them that they will make an even better raft than theirs if they do not act quickly. Hattori then suggests that they make an eco - friendly raft by recycling empty tins.

Later on, Shishimaru is running around, searching for tins. He finds one but gets run over by a car. He then yells at the driver of the car for driving carelessly.

Meanwhile, Kenichi and Shinzo are at a shop and ask the shopkeeper, an elderly lady, if they can borrow some tins, lying that they are organizing a tidy - up drive at the city. She agrees, thinking that they are so noble.

Meanwhile, after some ups and downs, Shishimaru finds a large oil cylinder in the waste ground, mistaking it for a giant can. He rides it away, but Kemumaki and Kagechiyo use some Koga - ninja splinters, making Shishimaru lose control of the cylinder and crash, scattering tins all over the place. Hattori then spots Kemumaki and Kagechiyo, and disguises himself as a collector of tins and borrows a hand-cart. Kemumaki and Kagechiyo find the cart and steal it. Hattori, still in disguise, finds the two and has them pull the cart to the river banks. After Hattori's raft is made, he and Kemumaki engage in a fierce duel in the water on their rafts, ramming each other until Hattori writes Kemumaki's raft off by pushing it onto the river banks. Hattori then sails away, with Kenichi, Shinzo and Shishimaru in tow.