Kouya Marino is the main protagonist of the Crush Gear Turbo series. He is a member of the Tobita Club and the younger brother of Yuhya Marino, a legendary Gear Fighter. Like many Gear Fighters, Kouya dreams of becoming a World Cup champion. Hence, the anime’s storyline revolves around his struggle to become the greatest Gear Fighter.
Kouya’s Crush Gear is Garuda Eagle which is inherited from Yuhya, and later on in the series, Garuda Phoenix. He is also seen using Battlehawk during the elimination match in the first episode. During his participation in Gear Pancratum as Sukiyaking, he uses Ark Cavalier which is given by Sean Firestone, a Gear Master whom he met in San Francisco.
Kouya is shown to have brown eyes and hair which has bangs over his forehead. His usual outfit includes a white hoodie jacket with red folded sleeves and hood, as well as a yellow long-sleeved shirt underneath with blue sleeves and collar. He has a black belt with a pouch for storing his Gear (as shown in episode 2), a pair of blue cargo pants, light blue socks, and a pair of white sneakers with a thick lining of red on its sides.
In his younger self (four years ago), Kouya was seen wearing a green shirt with the word "TOP" in orange on the center. He was also seen wearing a pair of black shorts with orange lining as well.
As Sukiyaking, he retains his yellow long-sleeved shirt with blue sleeves and collar. However, his trademark jacket is replaced by a red shirt with white long sleeves with black stripes on it, a star designed at the front of the shirt and a large number 1 on the back. He also wears a cap with a blue transparent visor.
In terms of becoming a great Gear Fighter (and ultimately, becoming the World Cup champion), Kouya has the determination similar to his brother. This is shown when he never gives up in discovering the secrets of Garuda Eagle. Kouya also puts his trust in his teammates, such as Kyousuke althought the Gear Master does several things that deemed questionable by others. Kouya's cheerful attitude is also shown when he sings during flights for international tournaments, namely the Asia Cup and the first stage of the World Cup. He has a liking for eating a lot (similar to his friend, Jirou) and crabs.
In the earlier episodes, Kouya has a little knowledge in Crush Gear despite being a sibling to a Gear Fighter. He does not know what a Gear Master is and he often relies on his friends for battle strategies and his Gear’s setting. As the series progresses, Kouya's skills in Gear Fighting improves and he eventually learns from Gear God about the connection between Crush Gear and the Gear Fighter's emotions.
Aside from that, Kouya is known to be an emotional Gear Fighter. He is occasionally seen to cry, for instance when he loses to Takeshi in the Manganji Cup and when Garuda Eagle being destroyed. He is also quite impulsive, notably when he accepts the Central Club's challenge for a battle in episode 6 without knowing their real abilities. Kouya lashes out his anger throughout episode 49 after Ming Wu tells him the truth behind Yuhya's death. He is also quite arrogant as seen in episode 21 after mastering Garuda Eagle's secret power. He is also (rarely) seen swearing in the Japanese dub most notably in episodes 12 and 49.
Unlike Takeshi, Kouya is also known to be protective in Crush Gears and dislikes destructions of them. This is notable when he stops Kyousuke from smashing Dino Spartan to the ground in episode 10 after losing to Kishin in the Manganji Cup, preventing the Gear Emperor from stepping on Caesarvern in the movie, stopping Cain's brother from smashing Ark Cavalier in episode 51, and his refusal to destroy Crush Gears throughout the Gear Pancratum arc despite the illegal tournament's rules.
He is also seen as an expert in baking which he inherited from his mother as seen in episode 58 when he seen baking dough for Jirou's red beaned buns.
During Yuhya's timeEdit
Kouya is the first person to see Garuda Eagle, a Crush Gear that will be used for the World Cup for Yuhya. After his brother's death, Kouya is assigned by his father to take care of Yuhya's mementos (i.e. Garuda Eagle).
Tobita Club's revivalEdit
Kouya becomes one of the members of the Tobita Club together with Takeshi, Lilika, Gomano and Momita. Once Kouya is late for the club's elimination match, and he is almost disqualified after Takeshi offers him a match where he has to beat him in one minute. However, Takeshi quits the Tobita Club and forms the Manganji Club, causing Kouya to be the only remaining team member along with Lilika. After Kouya learns that Takeshi lost on purpose during the elimination match, he begs him to rejoin the Tobita Club but to no avail. On the night of the Manganji Club's opening ceremony, Kouya challenges Takeshi to a rematch in an unfinished Crush Gear arena in the rooftop of the Manganji building. The rivalry between the two boys begins ever since.
Manganji Cup arcEdit
At the end of the Manganji Cup exhibition tournament, Kouya is supposed to face Satoru Todoroki until Takeshi interrupts the match and declares the tournament game over. It soon appears to Kouya and his friends that the true purpose of the tournament is to unveil Gaiki, Takeshi's newly built Crush Gear which costs 80 billion yen during its construction. Kouya suffers two losses in a row and Garuda Eagle is badly damaged.
Kouya and the rest of the Tobita Club takes a vacation in Hokkaido after being humiliated in the Manganji Cup. During such period, they go on a hiatus in Crush Gear fighting. He and Kuroudo are tricked by Kaoru by watching the Hokkaido Cup. There, they see Gaiki destroying its opponent as well as Kyousuke in the Manganji team bench.
Illusion Cup arcEdit
Buthokan Cup arcEdit
Initially Kouya is supposed to face Chota Aida in the Buthokan Cup semifinals until Jirou steps into the ring instead, forcing Kouya to face Nobiru once again. During the match, Kuroudo hears a bad noise from Garuda Eagle despite dealing a massive damage to Thunder Horn. Kouya wins the match; but his extensive use of the Shining Sword Breaker technique causes Garuda Eagle to disintegrate after the match.
Kouya finally faces Satoru in the Buthokan Cup finals using a new VT Crush Gear, .In the first two rounds, Kouya struggles to control his new Gear properly, which leads to an early loss. He manages to win the second round by a fluke, even after his gear sustains a Hairline Crack..Kyousuke is able to replace the fractured gear with the one of the internal gears from Garuda Eagle, that it fits perfectly. Kouya names his new Gear Garuda Phoenix an elegant creature which Kouya saw in a vision. As the third round begins Kouya throws Garuda Phoenix, and in a flash of amazement, his new gear changes colour, taking the look of it's former, Garuda Eagle. With his new gear reborn and it's true power realised, Kouya easily defeats Satoru, sealing the Tobita Club's victory at the Buthokan Cup
Asia Cup arcEdit
Kouya meets Wang Hu in a Chinese arena in Singapore. During the match, Tigeraid keeps dodging Garuda Phoenix and suddenly, his three teammates pound Garuda Phoenix.
In the two boy's meeting in the Asia Cup, the match is cut short this is due to a technical problem in the arena due to heavy rain. The match continues on the next day. During the second round, Wang Hu changes from being a cheerful boy to a ruthless Gear Fighter after Shining Sword Breaker damaged his medallion.
Kouya faces Takeshi in the Asia Cup finals where the match witnesses Shining Sword Breaker being used against Gaiki for the first time. In the first round, Gaiki is able to intercept the attack, while in the third and final round, Kouya uses Shining Sword Breaker to intercept King of the Dragon Fighters. The two attacks are evenly matched until Garuda Phoenix unfortunately loses to a ring out and runs out of battery power.
World Cup arcEdit
During the first stage of the World Cup, the Tobita Club pits against their long-time European rival, Weiss Ritters and the Si Xing Hu Tuan, At first, Kouya had a difficulty beating these two teams due to lack of cooperation. But they eventually defeated these two teams. However, at the end of the latter match, Kouya's wrist was sprained after slipping down while dodging Tiger Commander which is about to be blown out of the ring.
After the first stage, Kouya was left behind by his teammates in the airport until he arrives in San Francisco by Takeshi's private plane.
During the World Cup quarterfinal match, Garuda Phoenix and Tigeraid are evenly matched. Both Gears suffers two ring outs for the first two rounds. In the third round, Kouya's first Shining Sword Breaker attempt is blocked by a secret weapon similar to Tiger Force and probably Tiger Flare. Later, the secret weapon is deactivated and Kouya successfully hits Wang Hu's medallion which leads to its restoration, as well as Wang Hu's normal personality.
In the semifinal match, Kouya finally faces his brother's doppelganger, U-YA (real name Carlos Williams). Both Gears are evenly matched. However, near the end of the third round, Kouya is surprised that his opponent does not use the signature tornado release. Black Garuda Eagle eventually turns blue similar to Garuda Phoenix's color scheme. Later, both Gears go back inside the ring until Garuda Eagle is tipped by a spin block.
The deciding match of the Crush Gear World Cup championship takes place in the Manganji Hills. Kouya loses the first round, but he is able to finally hit Gaiki with Shining Sword Breaker in the second round after learning how Takeshi intercepted the attack. Garuda Phoenix is also able to unfreeze itself from the ice barrier from Gaiki's King of the Dragon Fighters which later multiplied to three. Kouya emerges victorious against Takeshi in the second round despite Garuda Phoenix running out of battery power. This is also the first time Gaiki ever lost to a ring out.
In the final match, Takeshi considers Kouya as his true rival. As a result, both of their ultimate attacks revealed their true forms. Garuda Phoenix's Shining Sword Breaker is portrayed as a Humanoid Warrior dressed in Phoenix Style Armor wielding a long sword, while Gaiki's King of the Dragon Fighters is shown as a Five-Headed Dragon. Despite losing its blade's tip, Garuda Phoenix eventually beats Gaiki which is lost to a ring out again. Kouya finally emerges as a World Cup champion.
- In an interview with the series producer Naotake Furusato, the creators have lost sleep over trying to name the main character. Furusato credits the director, Shuji Iuchi with the final naming. They decided to use "Kouya" as the name "had a ring to it like brothers", and that the name literally means "wilderness" in Japanese. Furusato added that the name "Kouya" sounded right for the main character and it made him want to see the character grow up big and strong. 
- In the English dub Kouya's name is pronounced as "Koo-ya" but in later episodes, it is pronounced right as "Ko-ya".
- Kouya is the only member of the Tobita Club whose both parents are explicitly seen in the anime.
- Jirou and Kuroudo's mothers are only seen in the series, but not their fathers.
- Kyousuke's father is only seen in the anime. In episode 10, Kishin (coincidentally) mentions Kyousuke's mother while taunting on his whining.
- In Lilika's case, her father plays a major role in the World Cup arc while her mother occasionally appears in a few episodes.
- Both of Kaoru's parents are not seen, but her uncle's family make their appearance instead.