Simplify the following text for a Grade 6 native English-speaking person.
Original: In Japanese mythology , Susanoo , the powerful storm of Summer , is the brother of Amaterasu , the goddess of the sun , and of Tsukuyomi , the god of the moon .
Simplified: Susano ` o is the brother of Amaterasu , the goddess of the sun , and of Tsukuyomi , the god of the moon .