Simplify the following text for a Grade 7 native English-speaking person.
Original: In Japanese mythology , RyÅ `` gÅ `` - jÅ ( ç `` å å \/ é 3\/4 å å ) is the undersea palace of RyÅ `` jin , the dragon god of the sea .
Simplified: In Japanese mythology , RyÅ `` gÅ `` - jÅ ( ç `` å å ) is the palace of RyÅ `` jin , the dragon god of the sea .