Father-Son Kamehameha (親子かめはめ波) is Gohan's ultimate attack in his Super Saiyan 2 form. First, Gohan fires a Super Kamehameha at the opponent, who struggles against the attack. Then, the spirit of his father Goku appears behind him in a Kamehameha stance and shouts to him "Now!!" Finally, Gohan pulls his hand back and throws it forward as he charges more power into the attack, overpowering the opponent and inflicting a massive amount of damage.
Gohan uses this attack in the final battle against Super Perfect Cell, who attacks with the Solar Kamehameha. Though Gohan manages to combat Super Perfect Cell in the Beam Struggle, the Bio-Android nearly overpowers the young Saiyan several times, due to having his arm broken when protecting Vegeta from Super Perfect Cell's attack. However, as Super Perfect Cell prepares to finish off Gohan, Vegeta blasts Super Perfect Cell with a Galick Blazer, completely distracting him. Seeing this chance and encouraged by Goku, Gohan unleashes all the rest of his power and power channeled to him by the spirit of Goku into the Father-Son Kamehameha, overpowering the Solar Kamehameha and destroying Super Perfect Cell once and for all.
Appearances in games
The attack appears in Dragon Ball Z: Idainaru Son Goku Densetsu, and can be used in Dragon Ball Z: Legendary Super Warriors, the Budokai series (including Dragon Ball Z: Burst Limit), the Budokai Tenkaichi series (where it was named Father-Son Kamehameha), Dragon Ball Z: Supersonic Warriors 2, Super Dragon Ball Z, Dragon Ball Z: W Bakuretsu Impact, Dragon Ball Heroes, the Raging Blast games, Dragon Ball Z: Ultimate Tenkaichi, Dragon Ball Z: Battle of Z, and Dragon Ball Xenoverse. It is Teen Gohan's Ultimate Blast in his Super Saiyan 2 form in the Budokai Tenkaichi series; in Budokai Tenkaichi 2, the technique is performed as a rush where Gohan uppercuts the opponent's chin, followed by a roundhouse kick which knocks them away, before charging the Father-Son Kamehameha.
It is called Family Kamehameha in Supersonic Warriors 2; first, Gohan fires his Super Kamehameha at the opponent, then Goku appears and charges more power into it, inflicting a great amount of damage. A variation performed with Bardock can be used if Bardock is in the team: Goku and Gohan use the technique but the opponent blocks it, then Bardock appears and adds his Final Spirit Cannon to the Kamehameha to blast the enemy, which knocks them off guard and allows them to be overwhelmed by the attack.
The move reappears in Dragon Ball: Xenoverse as Teen Gohan's Ultimate Skill. In the distorted history introduction cutscene to the Cell Saga, Dark Perfect Cell uses the move with the aid of his Dark Cell Jrs. to finish off Teen Gohan. The Future Warrior uses a similar technique to defeat Demigra in the games alternate ending.