Anime is notorious for its outlandish fight scenes. Characters can punch holes through mountains and shoot energy beams that can destroy whole planets. With so many powerful and amazing abilities, it can be hard to stand out among the crowd. This is why anime characters who fight in unconventional ways, like with their legs, rise above the rest in the genre. Fighting solely with kicks looks cool but limits characters to only using their lower half, so many characters have a special reason why they choose to (or have to) use mostly or only their legs in combat.
Sanji (One Piece)
"Black Leg" Sanji is probably the most famous anime character who fights with their legs. Although Sanji is a skilled fighter, cooking is his primary passion and focus. At a young age, Sanji was trained in both combat and the culinary arts by the infamous pirate Zeff. Zeff taught Sanji to not use his hands while fighting, as he could run the risk of damaging them. Sanji preserves his hands specifically while fighting, showing that he values his ability to cook over his fighting skill.
Despite his preference for cooking, Sanji has proven himself as one of the strongest fighters in the Straw Hat Pirates. His kicks are so powerful that they burst into flames, allowing him to set his opponents on fire. Sanji's kicks are also capable of easily breaking boulders and knocking out giant sea monsters. His legs are his greatest weapons, and they will lead him to his dream.
Tenya Iida (My Hero Academia)
Iida is a hero in training with a Quirk, or superhuman ability, that gives him an engine in each of his calves. These engines allow him to move at super speeds and deliver powerful kicks. Iida comes from a family with similar abilities who are all renowned superheroes. He works to live up to the legacy they have created and to always be fast enough to save those in need.
Because of his power, Iida is one of the fastest characters in My Hero Academia. At the start of the series, he was able to run at an average of 36.79 miles per hour. However, as the story has progressed, Iida has easily exceeded that speed. When moving at such speeds, Iida can crush metal with his kicks, and after undergoing special training passed down through his family, his kicks hit with the force of a rocket.
Morgiana (Magi: The Labyrinth of Magic)
Morgiana is a Fanalis -- a group of people from a far-off continent who possess superhuman strength and speed. Because of her incredible abilities as a Fanalis, Morgiana was kidnapped and sold as a slave. Eventually, with the help of her allies, Morgiana escaped slavery and now uses her monstrous strength to protect the people she cares about.
Morgiana primarily fights with superpowered kicks. Fanalis are known for their powerful legs that allow them to jump great heights and perform kicks that hit like lightning. Later on in the series, she meets an older Fanalis who trains her in martial arts and teaches her about the continent they come from. Morgiana's kicks are strong enough to take out multiple opponents at once -- she can even defeat massive beasts with a single strike.
Mikey (Tokyo Revengers)
Manjiro "Mikey" Sano is a rather short teenager who leads a biker gang. Despite his short stature, Mikey is considered one of the strongest fighters in both his gang and the whole series. To compensate for his height disadvantage, Mikey mostly uses kicks when fighting, and his fighting skills have earned him the nickname The Invincible Mikey.
Mikey carries a terrifying amount of power in his legs. He can upend cars with his kicks, which have been described as nuclear. He's also been shown to be able to lift an entire person with just one leg. Mikey moves at quick speeds and delivers powerful roundhouse kicks that can knock out opponents with a single hit. Even though he's only a teenager, Mikey displays strength and skill far beyond most adults.