Kinro is first introduced alongside Ginro, blocking Kohaku and Senku from entry into the village due to their policy on outsiders, staunchly refusing to let a potential threat in. Kohaku then resorts to threatening the brothers with a fight should they refuse. Senku, unamused by this, blows bubbles with a bar of soap, causing the two of them to freak out until Chrome explains what's going on.
His brother, Kohaku and him then witness a battle of "sorcery" between Chrome and Senku, being fascinated with every move both parties make. Eventually Senku dominates Chrome in arithmetic battle, thereby acquiring everything Chrome posseses.
His spear is dipped into a mixture of cinnabar and gold dust by Senku, the latter warning Kinro not to inhale smoke due to a toxic reaction. Kinro then witnesses his spear having a gold color, saying if Senku's apparent sorcery made it stronger. Senku confirms it's only for aesthetic purposes, since gold matches Kinro's name. Kinro firmly states that Senku can't buy him over with something like this, only to be enchanted by the spear's color in the sun and say that he doesn't necessarily have to take it off. Senku and Chrome, now cooperating as scientific partner celebrate in their success in bribing Kinro, with Ginro asking if they could do something about his spear as well.
Kinro's stauch personality still prevails when Senku tries to get into the village in order to inquire Ruri about her knowledge of modern stories. As the group fails to smelt iron properly as they don't have enough power or people, Ginro asks if he should go and help, greatly angering Kinro who orders him to stay at his post. Ginro complains about not getting a customized spear of his own, Kinro being appalled by Ginro's susceptibility to bribing. Ginro then tries to switch with Kinro, saying that they should trade lances since the latter apparently doesn't care much about his, which Kinro vehemently refuses.
As most of the village gets enticed by Senku's ramen, Kinro still vehemently refuses to associate himself with "sorcerers" by rejecting Chrome's offered ramen. His hypocrisy is called out by Kohaku who criticizes him for taking a customized spear yet refusing to eat simple food. A faint voice playfully calling for cola in pair with made ramen is heard, with Senku being startled by it as no villager should know about the drink in this age. Kohaku asks Senku whether the person who said it is his friend, Senku negating it. Kohaku then turns to Kinro and Ginro and apologizes for the interruption, but warns them the enemy is here. Kinro, Ginro and Kohaku then swiftly encircle the enemy who turns out to be Gen Asagiri, modern age's mentalist.
Kohaku uses Kinro's spear as a receiver for lightning charge, destroying it completely in the process. Kinro laments his broken spear while Kohaku apologizes and states it was necessary. When Ginro makes fun of him for losing his spear, since he never let anyone else use it, Kinro repeatedly pummels him before storming off in anger. Gen manipulates him into aiding the creation of the hand-cranked generator, claiming that they could use it to fix his spear.
Kinro and his brother are approached by Kohaku de jure offering them her sister's hand in exchange for saving her from Magma. Kinro scolds Ginro's immediate focus on Ruri's superficial qualities and states a gatekeeper's answer is irrelevant. However, he understands the problem and that Senku is not evil, so he offers his help in the village games and begins training with Kohaku in order to prepare for the competition.
Continuing their training with Kohaku, the two brothers talk about Kinro's sight in private. Ginro criticizes Kinro for not telling people about his sight problems - blurry eye sickness as villagers call it. Kinro, as staunch as he always is, responds that a man should make no excuses for his failures.
Kinro and Ginro form an alliance in order to convince Senku to make them their respective spears, making an excuse that it will make fighting and practicing easier. Kohaku concludes they just want their spears customized and that it holds no battle value whatsoever.
Kinro is appalled by Senku, Chrome and Ginro's plans on rigging the village games. He states he will not participate in such plan and only abide by rules. Senku and Ginro state they have no problems with it, as his only job is to beat Magma. Kinro asks whether Kohaku is fine with having the village games fixed like this. She agrees with the trio since it will save Ruri.
He is outraged by his brother yet again when the latter drinks all of the fighting supplement made by Senku. With no options left as he was positioned to fight Magma in the first round, he approaches Magma who offers him a place as his subordinate. Magma tries to humiliate Kinro by making him lick his shoes as he has no chance of winning. Kinro rebukes this claim and says that he is fighting for his comrades, and won't fall under any circumstance. He then rushes Magma with his spear, thereby initiating the village games.
Kinro is initially pairing Magma and even pushing him back, forcing Mantle to try to barge into the match with rocks, only for Chrome to remind him Jasper is watching so no interference will be allowed. Magma is forced to make distance between them, as Kinro squints since his vision is starting to get impaired.
Suika notices this and concludes that Kinro has "blurry eye disease" just like her. Kinro hopelessly thrusts his spear into Magma, the latter easily parrying his spear as it misses the target. With a flury of punches, Magma sends Kinro collapsing onto the ground. Magma approaches him and once again offers him a spot of a subordinate if he licks his shoes, only to be interrupted by Suika who throws Kinro her helmet in order to adjust his vision. His eyesight improved, he parries all of Magma's strikes and then sends a barrage of hits, making his opponent falls to his knees. He thanks Suika and Senku for the lenses and states he surpassed Magma long ago in terms of strength, having only needed to overcome his vision problem with the "eyes of science".
As the battle comes to an end, the village celebrates Kinro's strength. A seemingly defeated Magma asks whether carrying that mask is enchanted by sorcery, saying that if Jasper confirms it's not against the rules, he will accept defeat without complaints. Kinro agrees with Magma. Jasper then says he considers the mask merely as a part of clothing and not direct interference in form of an attack, so it's accepted in a fight. Suddenly, while Kinro isn't paying attention, Magma quickly rises and strikes the former on the head with his spear, breaking Suika's helmet and knocking Kinro out. Ginro rushes to his brother who awakens shortly after the hit, Ginro saying he's glad to see him well after Magma's sudden assault.
Kinro observes his brother's fight with Argo, fascinated at Ginro's confidence. After Ginro wins the fight and rushes off, his brother follows him. Kinro and Suika comment after seeing Ginro battered up that he is very likely unable to continue fighting.
At the games' end, once it's certain that the Kingdom of Science will win the leadership of the village, Gen states that it's his time to leave; considering the ever faithful to the rules Kinro won't agree with him staying inside. Kinro gets reminded of this and notices he got wrapped up in the village games so much that he wasn't even aware of it. As Ginro suddenly decides to force his win onto the competition since he misunderstood Ruri's formal statement, Kinro is time and time again disgusted with his brother's behavior.
Once Senku wins the battle, acquires the position of village chief and alcohol, he promptly divorces Ruri. An enraged Kokuyo orders Senku be caught, only to be stopped by Kinro who vouches for the mysterious outsider's nature. Kinro states he has observed and confirmed that Senku is not a dangerous man, seeing his resolve and nature - which Ginro agrees with.
Kinro once again vouches for Senku as Ruri's condition worsens, agreeing with Kohaku that he believes in him and science, prompting Kokuyo to release the scientist and let him treat his daughter.
Kinro guards the bridge, telling his complaining brother he should respect the gatekeeper codex despite the celebration of a new cheif. He notices something amiss, telling Ginro to notify the village and destroy the bridge if necessary. Soon enough, invaders from the Tsukasa Empire attack. Kinro easily sweeps aside the grunts before he battles the leader Hyoga, who notes on his poor eyesight. Kinro holds his own but is wounded in the process and nearly falls off a bridge, though he grabs Hyoga's leg. Despite urging Ginro to cut the bridge, Ginro refuses to kill his brother. Thanks to Senku deceiving the enemy into retreating, Kinro survives the battle.
Ginro keeps panicking about Kinro's wounds while his brother assures him that he will survive and recover. He is given acetanilide, a painkiller along with sulfur medicine by Senku in order to treat his injuries, Senku claiming he will be completely recovered by tomorrow.
The next day, the group notices he pretends to be fine but is barely holding on. Angered, Kinro warns them of another possible impending attack from Tsukasa's group, saying that he can't simply rest while having a job of a village guard. Senku claims that he can in fact predict when the next attack is going to come. Later on, Kinro receives glasses that fix his shortsightedness.
Eventually, as Tsukasa's group returns for another assault on the village, Kinro and the rest of the warrior team counter them while being equipped with katanas made by Senku.
He battles Hyoga again, with help from Ginro, Kokuyo, Magma, and Kohaku. Kinro is able to cut through the enemy's defense but he is overwhelmed by Hyoga, though still helps Kohaku in battle before he is shocked at Hyoga's spear breaking because of Gen - whose true allegiance turned out to be with Kingdom of Science.
Kinro is horrified when Homura sets the village ablaze, before she easily dashes through them. He protects the evacuating villagers before Senku and the others get Hyoga to retreat. 
Once the cotton candy machine is crafted as a part of the cellphone making process, Suika enjoys the taste of the sweet along with the rest of the villagers. Kinro is also excited to hear that he won't need to use physical labor after the water wheel is created by Kaseki and Chrome. Along with his brother, he rejoices at the "age of energy" before Kohaku has them trained for the impending battle.
After Senku realizes that Byakuya Ishigami left a recording message for him, Kinro is surprised by Senku desecrating Byakuya's grave before they discover the CD. Once the record player is made, Kinro is amazed by hearing the recording of village founder and Senku's father and the song by Lillian Weinberg.
He stays behind in the village and takes part in the ruse to deceive Homura. Kinro is soon surprised by Homura knowing his name along with the other villagers.
After the battle, he witnesses Tsukasa's sister being depetrified, while amazed to see a statue freed for the first time.
When Yuzuriha built a fashion store, Kinro is used as a model and wore a more modern outfit.
Kinro helps in the building of the Perseus.
He is later depetrified along with Nikki and Magma. He does worry about his brother, after he is told of the latter's fate, but is assured he will be revived.
He regains his golden spear and decides to ensure the sacrifice of his brother is not in vain. He is able to overwhelm several of the enemy soldiers.
After the group realize they were tricked by Ibara, they decide to head back for the Perseus which is already been stolen by the enemy. 
They break off into groups with one going off to reveal the true state of the Head of Petrification Kingdom while the others stop Magma from wasting all the ammo in the . gun. When concerns are made about how they will find him they soon here shot in the duties direction. 
Once back on the ship they engage the enemy in battle, before Mozu arrives. Kinro attempts to hold him off but is knocked aside. His allies to retrieve him and they all proceeded to run but are cornered. However, this was a ruse and Senku revives Hyoga who Kinro loans his spear to Hyoga.
He helps with crafting a tube for Hyoga's spear and watches in awe, as he overwhelms Mozu with his skill.
He is later repetrified by Ibara along with the rest of the island.
Kinro is revived by Senku and is pleased when he watches him depetrify Ginro, whose wound is healed and Kinro compliments him on his good job.
He helps in reviving all those petrified on the island. When Ginro begins acting cocky to Matsukaze, Kinro comments that he has no right to be smug. 
During the party after the poker game, a drunk Ginro asks Matsukaze to tell the story of when he was his lord and Kinro remarks that wasn't him. Matsukaze then tells the tale of how the Petrification Weapon got to Treasure Island. When Hyoga, Mozu, and Homura are revived, Ginro sneaks away as they joined Matsukaze and Tsukasa in weapons training. Kinro is approached by his brother to train him instead and he obliges.
After the long voyage, he is excited to reach land.
When the crew set camp at night, Tsukasa notes there is danger lurking something that is supported by other warriors. After Ginro states he isn't worried because of the strong group, Kinro remarks on his sheepish nature. Tsukasa alerts everyone to retreat inside the boat, where they could take cover. Surely enough, bullets rain down and everyone ducks for cover. Kinro is able to dodge the attacks, thanks to his allies. As the bullets are fired, he panics and questions what is happening before they retreat. 
As the enemy pursues them in the river, Kinro is annoyed by Ginro's panicking, since he wasn't touched by the bullets, unlike Matsukaze. He then helps Taiju, Kohaku, and Kirisame in taking down the aircraft, which is then procured on Senku's orders.
Kinro is further disturbed by Senku's continued kind behavior. He is utterly flabbergasted, when Senku bluntly asks Luna about Xeno. However, he is later overjoyed by eating ice cream when its recreated.