planet x

Years ago, planets X and X, Jupiter and Saturn, had problems. X was someone vengeful and serious before all the trouble, and when the problem happened they were still children. It wasn't when Earth told Jupiter...

Earth: Jupiter, look, I found a requested planet, come!

Jupiter; eh?? Well, let's see
Jupiter and Earth headed to the place Earth indicated and there they found it. Planet X was there, with a serious and murderous face.

Jupiter was surprised to see him after so many years since they were children. He was terrified because he knew that X would come for revenge.

X saw Jupiter and looked at him coldly
Earth asked if they knew each other, and Jupiter said no.

x turns around and hurtles towards Jupiter

x: So we don't know each other, huh?!

Earth tries to separate them

X wants to be understood but doesn't want to forgive Jupiter for what it did to him, which was expelling him from the solar system. He hated them, but little by little Jupiter and Saturn would feel something for him, and X too.