"Backflip and fire a Kamehameha! Use 300 Stamina to fire it even while being damaged! You can also use Ki to fire additional blasts!"
The user charges their into their hand (usually while chanting the familiar KA-ME-HA-ME-HA) then fires an energy wave at the opponent. This technique is often performed when one of the user's arms are lost, thus preventing them from performing the original version. Prior to using the technique, the user does several back-flips to distance themselves from their opponent.
At the end of his Fierce Combination Future Gohan utilized this technique after he lost his arm defending Trunks from the Androids.
- DUAL One-handed Kamehameha - A two person team attack variation that appears as Future Gohan's Dual Ultimate Skill in Xenoverse 2 after the 1.09.00 Update which he teaches to the Future Warrior after his training with them has made him recall memories of his mentor, Future Trunks, and his late father after bonding with the warrior while training them. Despite its name and description, this technique is actually a DUAL One-handed Kamehameha mk.II as both user fire the mk.II version's secondary blast during the Dual Ultimate itself.
Video Game Appearances
"This technique can also be used when taking damage from an opponent. Performs a backflip to avoid attacks. Pressing the button again increases the technique's power."
— Dragon Ball Xenoverse 2 Tutorial description
One-Handed Kamehameha mk. II was first named in Dragon Ball Xenoverse 2 where it appears as one of Future Gohan's Ultimate Skills. It allows the user to use ki to fire an additional blast by imputing the button command a second time.
"When I fight with you, it brings back all kinds of memories. I think of my dad, who died of heart disease... I think of Piccolo, who trained me... And I think of Trunks, and how we both kept training together. That reminds me. There was something I wanted to try. I couldn't do it before, but... I think maybe I could manage it with you. Would you be willing to indulge me for a while?"
— Future Gohan before teaching his Dual Ultimate in Dragon Ball Xenoverse 2
After the 1.09.00 Update, the Future Warrior can learn Future Gohan's DUAL One-handed Kamehameha as Future Gohan's Dual Ultimate Attack skill after achieving "Partner" level (maximum friendship) with him as an Instructor. Future Gohan notes that while training them he recalled memories of Future Piccolo, Future Trunks, and Future Goku, before asking them if they would be willing to team up and attack together before teaching them his Dual Ultimate.
"An Ultimate Attack requires the ultimate partner! Attack as a pair with a One-Handed Kamehameha!"
— Dragon Ball Xenoverse 2 Dual Ultimate Skill description
Despite its name and skill description, it is actually a team attack version of One-Handed Kamehameha mk.II as the users fire a secondary blast as part of the Dual Ultimate. Presumably the name DUAL One-Handed Kamehameha was used instead of a more accurate name like DUAL One-Handed Kamehameha mk.II in order to save text space for both the skill and its description, or the mk.II was dropped as Future Gohan only has a single Dual Ultimate, thus it was removed in order to prevent confusion as there would be no DUAL version of Future Gohan's standard One-Handed Kamehameha (an Ultimate Skill which appears as part of Future Gohan's custom skillset after the update). The DUAL One-handed Kamehameha can be added to Future Gohan's custom skillset through Partner Customizations even before the skill is learned by the Future Warrior. The skill is only required to initiate the attack itself while the secondary assist that (if successful) triggers the DUAL Ultimate can be performed by Future Gohan, the Future Warrior, or Time Patrollers regardless of the skills (or skillsets in Future Gohan's case) they have equipped. The strength of the Dual Ultimate increases as Future Gohan's Partee Gauge fills up which can be done by bringing him along on missions, performing the Dual Ultimate in battle, and selecting him as their partner during the events of the Infinite History Saga.
Though he usually has both arms in most video games, Future Gohan will still use this version of the Kamehameha as part of his one-handed fighting style that is based on his fighting style from the Dragon Ball Z: The History of Trunks special.