Episode 4

Synopis
After setting out for the return point, the Gurren Brigade stop for some training. Kamina says that the unification of Gurren and Lagann is not graceful or manly enough, so he tries to make it more so through training. This training involves Kamina inside Gurren throwing rocks at Simon.

Some strangers are passing by and see this, thinking it is a Gunmen attacking a human. These 4 attack Kamina and with some strange weapon that seems to effect the Gunmen quite well. After they knock Kamina down they learn he is a human and they introduce themselves as the Black siblings. The oldest and only brother Kittan, the elder sister Kiyoh, the middle sister Kinon, and the youngest Kiyal. They claim to be after a 16 faced Gunmen.

When all of their stomachs start rumbling they go hunting and pick up some weird fuzzy thing that is just lying there. They are about to eat it when it turns out to be beastmen...16 of them to be precise. The beastmen return to their gunmen and fuse together. Simon tries to fuse with Kamina several times, but every time Kamina throws him off saying it is not manly enough. Eventually Simon gets flung in the air and Kamina decides that a mid-air fusion would be the most manly. They fuse together and start fighting but still get pushed back.

It turns out if Kamina and Simon are hungry, Gurren-Lagann gets weaker. So being a true hero, Boota gives part of himself to Kamina and Simon to eat. After their food they get strong enough to fend off the beastmen. After the fight the black siblings and the Gurren brigade go their separate ways.