Let's earn some Money (アルバイトの道はきびしいでござるの巻) is episode 3 of the Ninja Hattori-kun 1981 anime.
On seeing Kenichi's desire on buying an expensive train set, Hattori pokes his nose into Kenichi's work. Kenichi is angry - but will he realise that Hattori is working for his sake?
Kenichi is hoping to buy a very expensive train set that is being advertised in the magazine he is reading. Hattori sees this and offers Kenichi his savings. Kenichi is about to buy the set... when Mrs Mitsuba swipes the lot and tells Kenichi not to take advantage of Hattori's money.
Fuming, Kenichi decides to perform some odd jobs, starting with massaging his father. Mrs Mitsuba asks Kenichi to go to the corner shop, but Kenichi is still busy. He gets 100 Yen and goes to perform the task his mother gave him - only that Hattori has done it himself. Hattori returns with the shopping, and Mrs Mitsuba pays him. Kenichi is livid and vows to stop Hattori from poking his nose... but Hattori goes and buys chewing gum from the post office shop for Mr Mitsuba, fixes the roof (leading to Mrs Mitsuba making a biassed comment about him and Kenichi) and gets paid a million pounds... OK then, a few hundred Yen.Mr and Mrs Mitsuba leave for the shops, leaving Kenichi and Hattori in charge of the house. Kenichi gets his foster brother to clear out, but Hattori is undaunted. He leaves for a restaurant and gets a job as a delivery boy - or a delivery ninja. He delivers seven packages of spaghetti to a customer, and makes a man on a motorbike crash into a lamppost. The rider survives, but is dazed.
Off - screen, Hattori delivers the batch and goes back to work. Upon returning, the manager of the restaurant assumes Hattori disposed of the spaghetti and gives him the sack. He however realises his mistake and apologises to Hattori, though he is not seen doing the job in later episodes. He then goes to the toy shop and buys the train set.
Back at home, Kenichi and his parents are waiting for Hattori. He arrives soon and gives Kenichi the train set. Kenichi realises his mistake and is reduced to tears.