Sunlight Heart
Kakugane Serial Number(s) LXX (70) (disguised formerly)
Black Kakugane III (3)
Creator Kazuki Muto
Form Lance
Main Color(s) Silver, bright yellow and red
"Its Brightness is like the Sun!" - Nobuhiro Watsuki

The Lance Buso Renkin Sunlight Heart (突撃槍の武装錬金 サンライトハート Ransu no Busō Renkin Sanraito Hāto) is the Buso Renkin of Kazuki Muto. Seeing as the Kakugane doubles as his heart, his Buso Renkin plays a unique and critical role in Kazuki's survival.


Once invoked, his Buso Renkin, Sunlight Heart, takes the form of a spear-lance with a large decorative cloth attached. Kazuki was told his personality fit as a spear so his Kakugane took that form, because he liked to poke his nose into other people's business.

Powers & AbilitiesEdit

Energy Cloth: The cloth of the lance turns into an energy force when it resonates with Kazuki's willpower. The cloth's energy can be used as propulsive kinetic energy for forward charging, or, dissipating the gravitational forces of a fall. This ability is the origin of its name as the light it radiates shines like the rays of the sun.

Enhanced Durability:The weapon can be scratched but is difficult to completely destroy .


Sunlight Slasher

Sunlight Slasher

Sunlight Slasher (サンライトスラッシャー Sanraito Surasshā): (formerly Jousting Slasher) A charge attack propelled by the cloth's energy. Kazuki's fastest attack.

Sunlight Flasher

Sunlight Flasher

Sunlight Flasher (サンライトフラッシャー Sanraito Furasshā): (formerly Jousting Flasher) A flash of light from the cloth to blind enemies. Doesn't seem to have any direct offensive use, other than as a distraction.

Sunlight Crasher

Sunlight Crasher

Sunlight Crasher (サンライトクラッシャー Sanraito Kurasshā): (formerly Jousting Crasher) An attack which wraps the cloth around the lance to increase the overall speed and destructive force of the charge. Kazuki's most powerful attack. Faster than usual charges, but not as fast as the Sunlight Slasher.


  • Its size makes it cumbersome in close combat. However, Kazuki has eventually mastered the lance to the point where this is rarely an issue.
  • Because the Kakugane doubles as Kazuki's heart, the Sunlight Heart is a part of his body. Complete destruction or prolonged seperation results in death.

Other FormsEdit


  • Nobuhiro Watsuki states that originally it was based on the Missile Gauntlet wielded by a superhuman soldier named Surge Thunderarm (a discarded character he also based him on) in his previous manga Gun Blaze West. It was one of his favorites: A huge missile mounted on a gauntlet, attacking the enemy with a splendid creative weapon along with yourself. But this idea was chucked out because gimmick weapons of the "one-handed device" style were largely used in other shounen manga and anime.
  • Watsuki got the idea to make the weapon a lance after watching the movie "A Knight's Tale"
  • Watsuki states that the design of the weapon is actually that of Jinguuji Norijuki, the best selling active designer in anime and manga video games.