Actually, the cause of this matter wasn't very complicated.
It was already hard for the Galaxy Aristocrats from Beta Planet to conceive a child, so each and every child from Beta Planet would be treated by the entire race like a treasure.
And 800 plus years ago, there was a young woman on Beta Planet whose character was extremely cold and wasn't moved by any man. However, her looks were extremely beautiful, and therefore attracted the affection of many young men. Thus, a tragedy happened. After the woman turned 18, countless men started wooing her. Since there was a competition to fight for something, there would naturally be conflicts.
Actually, up to here, it wasn't much. It was human nature to chase beautiful things. Outsiders weren't suitable to interfere with things between the young people too. Yet, just at this timing, an accident happened.