Buso Renkin is the story of teenager Kazuki Muto who dies trying to save a girl who was being attacked by an eerie monster. The following morning, Kazuki wakes wondering whether it was all a dream. But the girl, the monster, and his death are all real! The girl, Tokiko Tsumura, was actually trying to slay the homunculus (a beast that can take the form of humans, but whose main source of food is people), but Kazuki got in her way. To revive Kazuki, Tokiko replaces his heart with a "kakugane," an alchemic device that allows him to summon a lance with which to fight the monsters. It turns out that Tokiko is a member of Renkin Kenshi (Alchemist Soldiers), an organization sworn to protect the world from the diabolical creatures. Soon, Kazuki joins Tokiko in her quest to terminate the sinister being that creates and controls the homunculus.

Talk about being at the wrong place at the wrong time! High school student Kazuki Muto had no clue what he was in for when he rescued damsel in distress Tokiko from a monster known as a 'homunculus'. Disguised as humans who actually eat humans, homunculi are malevolent creatures that affix themselves to people's brains, and once fully grown, the only thing that can annihilate them is a weapon called Buso Renkin!

Follow the adventures of Kazuki after he discovers that it was actually Tokiko who saved his life by implanting a kakugane, an alchemical device that transforms into a buso renkin, to replace his heart!

"In Watsuki's modern-day follow-up to his smash Ruroni Kenshin, we meet high school student Kazuhiko Muto, who dreams of rescuing a pretty schoolgirl from a hideous, tentacled beast. Is this vision just a product of his slumbering imagination? To his horror, Kazuhiko discovers that his dream is actually a terrifying reality and the creature that he battled is a 'homunculus,' one of a legion of man-eating monsters who hide among the general population in human guise until they can prey upon their victims. Luckily for Kazuhiko, the girl he rescued in his 'dream' is a sorceress who seeks to wipe the homunculi from the face of the earth and has altered Kazuhiko's body with the power of alchemy and a talisman called the Kakugane, rendering him virtually unkillable, highly skilled in the fighting arts and empowered with the Buso Renkin, a mystical lance that can defeat the homunculi. Watsuki offers up strong artwork, clear storytelling, hyper-kinetic action, monsters, arcane weaponry and characters crying out their special moves, such as 'Valkyrie Skirt!' and the titular 'Buso Renkin!' This first volume is mostly setup, but Watsuki's fans will want to stay around for the ride." Publishers Weekly (Copyright Reed Business Information, Inc.)

Kazuki Mutou is mortally wounded saving a girl from a strange monster, but is given a new life through the power of the alchemically-made Core Iron. Along with a second chance, this grants him the ability to use his own Busou Renkin, or Alchemy Weapon. Joining forces with Tokiko, the Busou Renkin user he'd saved earlier and who gave him the Core Iron, he uses his newfound powers to fight the malevolent Homunculus monsters and protect his friends and the rest of mankind.

Born on May 26, 1970. Born in Tokyo and grew up in Nigata. Graduated from Nigata Prefectual Nagaoka High School. His blood type is A. He won an honorable mention prize in the Weekly Shonen Jump. "New Manga Hop Step Award" with the work Podomakku. Later, while he worked as an assistant, he presented works such as Sengoku No Mikazuki. (Crescent Moon in the Warring States) and Rurouni-Meiji Kenkaku Romantan (Meiji Swordsman Romance Story). The serialization of Rurouni Kenshin started in 1994 and concluded in 1999. His hobbies are to draw, read, play video games, read American comic books, and make model figures.