He along with Yusei Fudo, Crow Hogan and Jack Atlas was a member of Team Satisfaction during their younger years, and the four of them are adoptive sworn brothers. However he disappeared when he was arrested by the tyrannical Security and sentenced to prison where he starved to Death, after which he was revived as a Dark Signers with the Dark Sign of the Giant Geoglyth.
Upon his defeat his body decayed into darkness but was revived after the defeat of the King of the Netherworld and reformed his ways becoming a hero to the people of Crash Town which was renamed Satisfaction Town in honor of his old team. Where he stayed and helped to rebuild the town.
Called Kalin Kessler in the dub, he is a primary antagonist in the first season (second season English release) of the TV anime: Yu-Gi-Oh! 5D's.
Joining the Dark Signers
Reunion with his "Brothers of Satisfaction"
Though unnamed at the time, Kiryu first appeared at the sight of the Old reactor, the base of operations for the Dark Signers as that was where the powers from beneath the Nazca Lines had emerged in the city. There he along with Demak listen as Rudger notes how the Signers had been assembled and than initiates their plan, first by using Shadow Drones, a subspecies as it were of Dark Signers which Rudger uses his ability to create. While two Dark Signer Shadow Drones appear in the city challenging Yusei and Jack respectively, the Dark Signers bolster their ranks by using the mind control ability of Rudger to turn much of Satellite's populace into a cult against the Crimson Dragon and lead victims deep into Satellite's depths.
Later while Rex explained things to Yusei, Kiryu was in Satellite at the Old Momentum, the ceremonial "tower" of the present day. Demak notes how this time the world will be theirs do to the mistakes of society. When Yusei returned the Dark Signers received word when he was at Deadulus Bridge and Kiryu proclaimed him as his prey and went to duel him personally. Rudger accepted and bid him on his vengeance.
When Yusei and Crow arrived near his location Kiryu used his ability to summon his Patron God in mist form which allert Yusei to their being a Dark Signer near by. Than as a welcome, he tossed "Blood Vorse" at the group which barely missed Crow, catching their attention. At first hooded he seems to recognize them but Yusei and Crow demand to know who he is, which he replies by pulling off his hood revealing his identity. A former friend named Kyosuke Kiryu.
Kiryu explains that he is happy to see them as Yusei had dragged him through Hell and he was going to return the favour. Crow says that while he didn't know about any "hell" his grudge was unjust, but Kiryu instead summons his Dark Geoglyth, a ten foot high wall of blazing violet fire which forms one of the newly missing Nazca Lines, the line of the Astronaut, but is inuniverse the Giant.
Rematch with Yusei
As a Dark Signer; Kalin wield the Infernity Deck. This deck relies on effect if the user has no cards in his hands. He also wields Hundred Eyes Dragon. But his most powerful card was Earthbound Immortal Ccapac Apu.
Geoglyth & Patron God
Kiryu is the Dark Signer who represents the Earthbound God (Jibakushin) Ccapac Apu. Representing a giant human(oid) with a blue lining and what appears to be a single Eye in the centre of its disproportionate head, and an additional eye-like marking in the centre of its chest on its muscular body.
Ccapac Apu's body is the most disproportionate of all seen Jibakushin. Its head is the most noticible, with no no and taking up some of the shoulder room. On top of its head are four flattened horn-like protrusions that could be, or a represention of, hair. Most likely the latter as these bumps are also present on the back of Ccapac Apu's figures where the points would be on human hands, however the bumps on the head flatten out like cylanders while the fingure bumps round out slightly before becoming flat. The bumps on the fingures are smaller the farther down the finger they are and are in three similar sizes. The bumps on the head are also in two sizes, the two farther up the head being taller than the ones at the side.
Its limbs are inparticular stout compared to its imposing physique. Rather than having three part arms its hands begin when the elbow ends extending slightly from their to show bulky palms and digits. Its legs are equally stubby being disproportionately short and with minimal features compared to the rest of it and to other Jibakushin.
- Kiryu's Shadow Mark, the Giant, is one of the disputed Nasca Lines. It is most famously called the "Astronaut" but it is believed by some to be of an owl and is called "the Owlman" after the English Cryptid because of the ambiguity. Archeologists, however, believe it to actually be of a Fisherman, and point out to the presence of a net within the geoglyth. Fishing was an important part of the Nasca culture and it is believed to be their main source of food as well.
- Kiryu's patron god represents his desire to put Yusei through all the fear and trauma he had to go through during his incarceration by Sector Security. The fact that Ccapac Apu is human(oid) in appearance represents the tyranny that sector security enforces on the people of Satelite.
- Ccapac Apu (Kiryu's patron god) is pronounced Cacapac but in the dub it is pronounced Cocopac.
- Kiryu is the only Dark Signer originating from the Satelite; Misty and Carly were from Neo Domino City, Rudger (while responsible for the Zero Reverse which created Satelite) died at the time of Satelite's creation and was only revived in the depravity, Bomber was from Peru, and Demak was from a cult.
- Kiryu was the only member of Team Satisfaction not to be a Signer; he is a Dark Signer instead. He is also the only member of team satisfaction to have his name changed in the dub as Yusei, Jack and Crow retain their names in the 4kids release.