Biography
Chujin Ketsukane (Or Japanese transliteration: 欠鐘主人) is a recurring character in Undertale Yellow. He is the husband of Ceroba and father of Kanako Ketsukane. He is deceased during the events of the game, but can be seen during flashbacks and while playing video tapes.
Chujin was a purple furred, anthropomorphic fox-like monster with brightly purple colored hair tied in a small ponytail. He wears large, circular, green glasses as well as a green montsuki with yellow accents.
Chujin is said to have been a kindhearted and hard-working monster, and a good mentor. His philosophy was that even though monsterkind is in a bad spot, being sealed off from the surface, monsters can collectively make the Underground a better place through little acts of kindness.
However, Chujin was very mistrustful of humans. He believed that humans are dangerous and they can not be trusted. This is largely due to a past incident in Snowdin, which involved a human attacking monsters. Specifically, this was the human child with the blue SOUL (Integrity), who had fallen into the Underground. She happened to attack a monster who was with Kanako, Chujin's daughter. Kanako herself was not hurt, but Chujin was shocked to hear the news nonetheless. He felt that his daughter could have died that day, and he wasn't there to protect her. This incident, coupled with the knowledge about the Great War between humans and monsters, is likely responsible for Chujin's attitude toward humans.
Despite this, in his secret VHS tape, hidden behind his tombstone, he laments the fact that one of his creations accidentally ended up killing a human, and appears to be very regretful. This shows that Chujin did not completely hate humans, and doesn't wish death upon them. Thus, it is likely that Chujin could have changed his point of view if he were to meet a kind human (like Clover on the pacifist route). However, it is notable that Axis' presence before the attack means that though Chujin may not have wished death upon humans, he did still intend to produce weapons to use against them even before the attack.
Through his recorded journal, Chujin is shown to have been arrogant and stubborn. He does not admit to his mistakes and hides his firing from Ceroba, as well as his plan involving a human SOUL from everyone until his death. He dedicates himself entirely to his work and uses his dying wish to burden Ceroba with finishing it, showing that he is very adamant about his plan being the key to saving monsterkind.
Chujin was once a hard-working engineer for the many machines of the Steamworks. Along being a husband and a father, he was a mentor to Martlet, the creator of Axis, and a beloved citizen of the Underground. Though he was such a beloved monster, unknown to even his closest relatives, he had a downfall with an impact on the Underground which rings on to the events of Undertale Yellow.
Clover gains this information through tapes he left behind to document his scientific endeavors, stating "I don't have much time these days for a written journal so I opted for video." In his time away from recording his introductory tape, he'd taken a trip to Snowdin with Kanako. While tending to something away from his daughter, Kanako and a friend she was spending time with (hinted towards being Dalv) encountered a human. This human, given clues from the game, is most likely the blue SOUL. After the human attacked Kanako's friend and fled to Waterfall, Chujin was filled with rage toward humanity. He adopted the idea that all humans are vile at their core and that monsterkind must be protected from them.
Given a secret tape found buried behind his grave, it can be assumed that Chujin had already been working on Axis - a machine built to protect monsterkind from humans after reaching the surface. With the human's attack fresh in his mind, it appears he ordered Axis merely apprehend the human, but Axis instead killed the human and collected their SOUL (most likely due to a malfunction). - Something that was said in the Genocide Route as something Axis did not willingly carry out - Though he displayed remorse for opting to do this instead of comforting his daughter, he decided that he'd hold onto the SOUL for future experimentation. After this event it's assumed that Axis would continue to be pitched to Asgore, failing each time to impress the king. During the eighth and final presentation to the king, Axis would malfunction. This time, sparks flew from the machine onto the king's flower bed, setting a patch of it ablaze. Though it was swiftly put out, the king's patience had reached its end. After thanking Chujin for his contribution to society, he relieved Chujin of his position at the Steamworks.
After this incident, Chujin lied to his family and friends by telling them that he'd simply retired. In secrecy, in a bunker he'd built under their family home, he would continue research into a way to combat the threat of humanity once and for all. After years of research, he'd finally come to a breakthrough in his research. He had found out that he was one of the few monsters who could call themselves a Boss Monster, which means that by proxy Kanako was also a Boss Monster. His hope was that with this information, he could devise a way to transform regular monsters into Boss Monsters, strengthening their entire nation and giving them a chance should another conflict spark against humanity. He came up with a plan centering around the fusion of a human SOUL and a Boss Monster SOUL, according to his theory one could extract from this fusion a serum that would transform regular monsters into Boss Monsters.
After coming up with this plan, Chujin would attempt to make it work with himself and the human SOUL he harvested with Axis previously. Unfortunately, in his own words, "Over and over, the subject rejected the fusion, and I think I know why. I'll be direct... My SOUL has deteriorated and I don't know how much longer I have." After failing to complete the experiment on his own, he recorded one final time requesting that Ceroba carry on his work- under the condition that Kanako remain separate from it all. He'd go on to pass away in bed peacefully, informing Ceroba of the bunker and the messages that await her below.
Chujin himself does not appear in the neutral route, though his presence is referenced by monsters and background details throughout the Underground, particularly in the Steamworks. Martlet's journal mentions Chujin as her mentor in regards to woodworking and later friend, though she remarks that he was displeased when she joined the Royal Guard. Monsters in the Wild East will periodically remark on Chujin and how his and Kanako's absence has affected Ceroba, giving the impression that the two have died.
Once Clover enters the Steamworks, they begin to find papers, notes and references to Chujin. In particular, a plaque is present for a "You Tried" award in engineering addressed to him, and notes throughout reference his contributions to robotics and less-than-ideal results. If Ceroba is present with Clover in the Steamworks, she will further expand on him when Clover finds these details and remark that he was hardworking and brilliant, and ignore most details that point towards his ineptitude. Ceroba will also pull the player into an alternate path through the Steamworks, finding a report stating that Chujin was fired, admitting that Chujin had never told them personally. She defends him and urges Clover to spare Axis, whom she views as the culmination of Chujin's work, and becomes enraged if they kill him.
While at Chujin and Ceroba's house, Clover and Martlet uncover a secret laboratory containing notes on many people Chujin and a series of videotapes, revealing that Chujin was in fact a stubborn and prideful monster, refusing to admit his failings and intending to work on himself and the human SOUL to aid monsterkind. Chujin reveals that he is a Boss Monster. After the Integrity human arrived and he was fired, he began working on a serum derived from a Boss Monster merging with a human SOUL designed to turn any monster into a Boss Monster, rendering monsterkind immortal and powerful enough to defeat the humans in war. However, the Integrity SOUL in his possession refused to fuse with him, and after excessive tests on his own SOUL Chujin had become sick. His tapes conclude with him imploring Ceroba to complete his research and claim the SOUL from the next pure-hearted human to enter the Underground before fusing it with a Boss Monster, though he stresses that he does not want her to use Kanako for this as his final wish.
A secret tape hidden behind Chujin's gravestone reveals that an earlier iteration of Axis was responsible for killing the Integrity human, and Chujin had chosen to send Axis after them instead of comfort Kanako and her friend. When he found Axis and the dead human in Waterfall, he took the SOUL, had Axis dispose of the body, and took it home to experiment, insisting that though Axis was dangerous, he had potential and could still be completed.
Between the phases of Ceroba's boss fight, Clover experiences flashbacks of Ceroba and Chujin, showing Chujin dying in his bed and imploring Ceroba to watch his tapes and continue his research. Ceroba would do so, and end up defying Chujin's wish and testing the serum on Kanako, resulting in her "falling down" and being sent to Alphys' lab. This sparks Ceroba's motivation to kill Clover and take their SOUL, so that she can perfect Chujin's work and ensure Kanako's death would not be in vain.
In the middle of the final battle with Martlet, a flashback is shown, expanding on their friendship and the scene where she tells Chujin that she got a job as a Royal Guard at a post in Hotland. It can be seen that Chujin becomes upset by the revelation, and the two have an argument on whether Martlet should potentially put herself in harm's way before a human. This is what prompts Martlet to steal her syringe from Alphys' lab, with the intent to use it should she encounter a powerful human.
