|Manga Debut||Chapter 142|
|Anime Debut||Episode 76|
The Water Box Weapon was seen used by Future Yamamoto for defensive measures. It is shown to be able to withstand Dying Will Flames to some extent. Yamamoto is also able to use this Box to support his Shigure Soen Ryu techniques, which require the use of water. The Water that comes out of this Box Weapon has the Rain Flame's Tranquility ability. When used in battle, the Water weakens/nullifies enemies' attacks and renders them useless, as seen when Yamamoto was fighting Nosaru, Yamamoto quenched the Storm Flames Nosaru projected with his Box Weapon. This weapon is similar to Shigure Souen Ryu's second form, "Rolling Rain."