|Title||Canguro del Sereno ver. Vongola|
|Cambio Forma||Knuckle's Maximum Break|
|Manga Debut||Chapter 240|
Kangaryuu is Ryohei's exclusive Box Weapon, created by remodeling a Sun-attribute Kangaroo. It is imbued with the Vongola's latest technology. After its remodeling, Kangaryuu gained boxing gloves, shoulder pads, metal rings around its chest and tail, a double-barrel cannon and a jewel with the Vongola crest in its forehead.
Powers and AbilitiesEdit
Like the original Sun Kangaroo, it also has the ability to store and shoot weapons that make use of Sun Flames from its belly pouch, such as the Sereno Gloves and the Sereno Shoes. Furthermore, not only it has the Sun's Activation from inside its belly, but the double-barrel cannons can also launch Activation bullets. By undergoing Cambio Forma and fusing with Ryohei after he had received those bullets, it brings Ryohei into an extreme battle state called "Maximum Break". It was also shown capable of flying by releasing Sun Flames from its feet.
- Boxing: Kangaryuu uses boxing techniques to perform his other techniques.
- Sun Enhancement Shot: Kangaryuu is capable of shooting pure Sun Class Flames from his double-barrel cannons.
- Cambio Forma: Knuckle's Maximum Break: After firing a blast of Sun Flames that carries an Activation factor that boost one's physical battle state carries a terrifying power, but Ryohei can only maintain it for three minutes due to the stress that it causes to his body.
- Taienrankuga (Flame Storm Sky Fangs): A combined attack with Uri and Alfin.