Lesson 24: Garu-Garu! What!? You're my Younger Brother!?

'''Garu-Garu! What!? You're my Younger Brother!?''' is the twenty-fourth episode of Juken Sentai Gekiranger.

Synopsis
Learning the werewolf to be his older brother Gou, Retu confronts him, using his silver cross to identify himself. At the Rin Jū Hall, refusing to rely on Rio and Mere in his campaign, Maku calls upon his bodyguard, Hihi of the Rin Jū Baboon-Ken, to herald the new Fierce-Confrontation Rebellion. Mere, remembering Long's words, decides to follow Hihi to understand the cryptic news he told her. Back at SCRTC, Xia Fu reveals that Gou used a forbidden Geki Waza in an attempt to try and seal Rio. When he learns that Rio evaded the attempt and now leads the Akugata, Gou is angered at hearing the news. But Gou is more vexed that Retesu is a Jūken artist, leaving SCRTC in a huff and confronting HiHi with his Shigeki until the presence of a golden aura causes him to transform into a werewolf as the Gekirangers arrive. Retu stays with Gou to try and calm him down while Jyan and Ran go to fight Hihi. Once Gou becomes human again, he refuses to let Retu go after Hihi and brings him to the church where they grew up to remember the events of their last meeting: with Gou having Retu vow to never practice the Jūken and focus on his art. Gou then attempts to reason and then punch Retu, but both failed as Retu tells him that he has chosen his path long ago, before being informed by Miki that Ran and Jyan are in trouble. Gou chases after Restu, witnessing his fight against Hihi as Super Geki Blue, who realizes the error of his ways in preventing Retu from his true calling in seeing his fighting style. Though defeated, Hihi enlarged himself and was soon knocked off into the nearby mountain by Geki BatFire. Gou later apologizes to Retu, and they leave the battlefield. However, thanks to an upset Mere, Hihi regains consciousness and assumes a Dorinki-empowered form, attacking the Gekirangers in full-fury.