One breakfast, at the table, Kenichi avoids the vegetables on his plate. Mrs Mitsuba points out his mistake to him, but he ignores her. When Shishimaru steals Kenichi's carrots, Kenichi warns him that he'll become a horse before trotting off to school. Mrs Mitsuba asks Hattori to do something; Hattori kindly complies.
Later that day, Kenichi comes home from school, to find tomatoes on a plate sitting on the table. When Kenichi refuses to eat them, Hattori uncovers the other plate - fat juicy carrots. Kenichi recoils, so Mrs Mitsuba says that he can have whatever he likes once he's finished eating the vegetables. Kenichi is still reluctant, so Shinzo and Shishimaru eat them with ease. Kenichi, assuming that they're actually heavily disguised sweets, tries a tomato - and is disgusted! Hattori and Mrs Mitsuba look at each other in shame.
At dinnertime, the family sit down to eat. Kenichi refuses to eat, so Mr Mitsuba tries to encourage him by telling him that this is a family dinner, and as everyone says their grace, Hattori tells Kenichi that boiled vegetables - the main course - are very tasty. Kenichi, ignoring him, downs his rice and marches to his room.
That night, Kenichi sneaks down for some chocs - but the fridge door bursts open with carrots and tomatoes! Going back upstairs, he meets an angry duo of veggies, who furiously order him to eat his vegetables, but their balloon bodies burst and they are exposed as Shinzo and Shishimaru! Kenichi is fuming.
Next morning, Shinzo and Shishimaru tell Kenichi to remmber his promise - only to have a raspberry thrown at them. Shinzo then has an idea and tells Shishimaru and Hattori of his plan.
Coming home, Kenichi runs into Yumeko Kawai, who is making carrot juice. Just then, he realises the truth and tries to get it out of her. Thankfully, Shinzo and Shishimaru are spying on him, and they go to fetch the real Yumeko. As Kenichi manipulates Hattori, he freezes him, takes off his disguise, and reveals himself. Just then, the real Yumeko turns up with Shinzo and Shishimaru.
At lunch, Yumeko tries to coax Kenichi into having carrot juice. Eventually, Kenichi relents and drinks it - and asks for a second helping. Hattori is pleased that his idea worked.