Juwān! …What's That? is the sixth episode of Juken Sentai Gekiranger.
A strange picture dealer named Pierre Fujishiro comes to SCRTC to obtain a painting from Retu, which is still incomplete. As Retu's past is unveiled, Rin Jū Gecko-Ken user Moriya of the Five Venom-Ken arrives to cause havoc. The Gekirangers intervene, but are overwhelmed by Moriya's unpredictable tactics and fighting style, forcing them to retreat. During another training session involving window-washing, Ran reveals to Jyan that just fighting to win is not always Retu's goal; to him, true victory is obtained when he beats his opponent at their own game. In their second encounter, Retu manages to knock Moriya off his wall with artistic feeling at his side, forcing a fight between him and Geki Tohja. Moriya reveals his Secret Ringi, Rapid-Growth Arm, much to the chagrin of Mere, as she assumed that Moriya was the True Poison user. Regardless, he is destroyed much to Mere's dismay, with only three left to spy on. Retu soon completed his painting afterward with Pierre asking to have it.