Pi Pi and Di Di Fight To Swim

Pi Pi is on left hand side, Di Di is on right hand side.
Di Di kicks Pi Pi away.
Then Pi Pi turns a u-turn and crawls on Pi Pi's shell.
Now Pi Pi is on right hand side, Di Di is on left hand side.
Now Pi Pi kicks Di Di away.
Di Di tries to swim towards, 
but almost can fight equally, 
Pi Pi kicks Di Di.
Then later Pi Pi crawls on Di Di.
Now Pi Pi is on left hand side, Di DI is on right had side.