The Mint Leaf (Sweet Potato in Japanese versions) is an obscure Kirby series item that first appeared in Kirby's Dream Land. It lets Kirby use his Air Bullet attack in the air without falling afterwards, essentially allowing him to rapid-fire his enemies. This is a reference to real-life sweet potatoes often being the cause of hiccups, and real-life mint leaves giving better breath. The reason for the name mismatch may be due to cultural differences, as the association between sweet potatoes and hiccups is not as strong outside of Japan; regardless, the regional difference has been solidified in Kirby: Triple Deluxe by making the item distinctly different in appearance between versions.
Kirby's Dream Land
The Mint Leaf first appears in Kirby's Dream Land, and can be found within the Float Islands, Bubbly Clouds, and Mt. Dedede stages. It is most notably used during the battle against Kaboola, where it does not run out until after the battle is over. When Kirby is under the effect of the Mint Leaf item, Kabula's Theme plays, much like when he is using the Superspicy Curry.
Kirby's Pinball Land
The Mint Leaf appears as one of the items which Kirby can eat in the bonus game for Kracko Land. When a Mint Leaf is eaten, it confers 1000 points, and has no additional effects.
Kirby: Triple Deluxe and Kirby Fighters Deluxe
In Kirby: Triple Deluxe's Kirby Fighters Sub-Game (and in Kirby Fighters Deluxe), the Mint Leaf returns as an offensive item with a similar function, appearing at random during most battles. However, instead of puffing manually, Kirby puffs out air automatically, pausing after every few puffs. When the ability ends, Kirby puffs out a giant puff of air. It now resembles a sweet potato in the Japanese version and an actual mint leaf in international versions.
Kirby: Right Back at Ya!
In Kirby: Right Back at Ya!, it appears in the episode Dedede's Raw Deal, in its original form as a Sweet Potato. However, its hiccuping powers come as a hindrance rather than a help to Kirby this time around. In the episode, Kirby eats it off of a sushi revolver. He is then attacked by an overgrown Squishy, and his inhaling powers are prevented by the hiccups that result from eating the sweet potato. As such, he starts off on the losing side of the battle. However, Tiff scares his wits out by saying he'll starve if his hiccups don't cease, which makes Kirby (who is known for his gluttonous nature) jump in fear and release his hiccups.
- Despite being based on a real-life food item, the Mint Leaf does not restore any stamina when consumed. As such, it does not count as food in the Kirby series.
Artwork from Kirby JP Twitter featuring Kirby and friends eating fried Sweet Potatoes.