Riku participates in the space-based G5 mission and single handedly takes on multiple Gundams. A Zeta Gundam and ZZ Gundam attack from both sides, but he destroys both. He is then attacked by a Hi-v Gundam’s fin funnels and uses his sword to destroy the enemy unit. With the mission over, Riku ranks in the top 10 of everyone who has completed the challenge. Kyoya sees that Riku is becoming stronger, and Rommel believes he could be a powerful opponent in the Raid Battle. Tigerwolf thinks about how Riku was a newcomer until just recently. Later, the Build Divers take a swim in the pool at their Force Nest. Koichi comments that he hasn’t seen Yukki recently, and Riku answers that he’s been busy. Tigerwolf shows up and invites Riku to join the Ryukosai, a friendly match of talented Divers hosted by Toraburyu. Tigerwolf wants a one-on-one battle against Riku to determine whose Gunpla is stronger. Some of the team wonder why Tigerwolf would want to fight Riku, and Ayame explains that it’s because he acknowledges Riku’s strength. Riku decides to take up the challenge. Magee visits Tigerwolf and comments on him inviting Riku to the Ryukosai. Magee recalls how impatient Tigerwolf was against him three years ago, but that battle resulted in Tigerwolf’s loss. Magee asks why Tigerwolf has lost his cool, and Tigerwolf answers that he feels like he’s drifted away from what he desires, but Riku has reminded him that he wants to keep fighting strong opponents all the way up to Kyoya. Yukki runs into Riku at The Gundam Base and asks about him fighting Tigerwolf. Yukki recalls what they learned from Tigerwolf and mentions the concept of “repaying the kindness” from Shogi, in which the student is able to take what they have learned to defeat the master.
The Ryukosai begins with multiple high level players like Kyoya and Rommel in the audience. Sarah feels like the 00 Sky has changed even though it doesn’t look different, and Riku explains that he improved it to face Tigerwolf. Shahryar tells Tigerwolf that he’s showing all his tricks to other players before the Raid Battle, but Tigerwolf doesn’t care. The match against Riku’s 00 Sky and Tigerwolf’s Jiyan Altron begins. Kyoya and Rommel notice that Riku isn’t carrying a rifle and wonder if he plans to match Tigerwolf’s close combat style. Tigerwolf gets an early hit and tells Riku one of his weaknesses is that his shoulder binders limit his range of motions. Riku responds with a new close combat mode where the shoulder binders are lowered to increase mobility. Riku gets in some hits but loses his sword to Tigerwolf’s punch. He then gets knocked down to the ground as Tigerwolf rushes in to perform his special attack, Ryukorodo. Riku responds by generating wings of light that cancel out the attack. He then rushes in with his own punch attack, and Tigerwolf responds by using lighting to power up and attack Riku with Raijin Thunder. Despite being damaged, Riku refuses to give up. The 00 Sky suffers further damage from Tigerwolf’s flamethrower, but Riku dispels the fire with wings of light and activates Trans-Am Infinity. He then generates a large beam sword and dispels a Raijin Thunder before slashing Tigerwolf. The 00 Sky suffers damage from several explosions, but Tigerwolf holds it up and tells Riku that he’s finally earned his special move. Tigerwolf is impressed that Riku’s move surpassed the Raijin Thunder, and Riku asks if he’s repaid the kindness yet. Tigerwolf tells him that he hasn’t because the special move ruined his Gunpla, so he needs to adjust for that. Tigerwolf tells him to repair his Gunpla and start over, and he kicks Riku away to win the match. After the battle, Tigerwolf is surprised to hear that Riku thought up the special move mid-battle. Riku vows to get stronger and keep fighting Tigerwolf until he wins. Tigerwolf laughs and tells Riku that he’s just like him. Elsewhere, the Game Master is informed that the bug affecting the game keeps moving around.
Riku climbs the ranks by competing in the G5 mission and places himself on Tigerwolf’s radar for a showdown. In preparation for the difficult battle, Riku modifies the 00 Sky to allow it to perform better in close-range combat against Tigerwolf. The actual battle takes up the second half of the episode, with Riku understandably at a disadvantage for most of the fight. Thankfully, although Riku creates a special move on the fly that deals considerable damage to Tigerwolf, it’s not enough to win the match. This is probably one of the few times in the series aside from the fight with Tsukasa where Riku feels like he’s being genuinely challenged. Otherwise, it always feels that he just succeeds by luck because the story demands it.