Episodes
While delving into the upper layers of the Abyss to search for relics, Riko and her partner Nat become separated. Riko then sees ...read more While delving into the upper layers of the Abyss to search for relics, Riko and her partner Nat become separated. Riko then sees Nat about to be eaten by a crimson splitjaw and draws the beast's attention in order to save him. However, Riko gets cornered by the splitjaw and is about to be devoured when it is suddenly chased off by a powerful energy blast. Riko traces the source of the blast back to a robot boy who has fallen unconscious, and she and Nat carry him back their home at the Belchero Orphanage. With the help of her friends, Riko is able to revive the robot boy, who she names Reg. She then takes him outside to show him the town of Orth, which sits on top of the Abyss. show less
Riko and her friends attempt to figure out exactly what Reg is, but cannot find anything mentioning a robot in the list of ...read more Riko and her friends attempt to figure out exactly what Reg is, but cannot find anything mentioning a robot in the list of recorded relics recovered from the Abyss. Realizing that Reg will be taken away and dissected if he was ever found out, Riko disguises him as a regular orphan and arranges his enrollment in the orphanage. As a member of the orphanage, Reg will be trained to be an Abyss delver like Riko. Later, Riko's uncle Habo returns from an expedition to the Abyss, carrying the white whistle of Lyza, Riko's mother, as well as a sealed document. As the town celebrates the return of Lyza's whistle, Jirou tells Riko about how she was born in the Abyss, and Lyza used a rare relic to return her safely to the surface before disappearing on another expedition. Riko is then given Lyza's whistle and is allowed to observe the sealed document. In it, Riko finds a drawing of Reg as well as a note from Lyza saying that she is waiting at the bottom of the Abyss, hinting that Lyza is possibly alive. show less
Upon reading the note, Riko decides to descend into the Abyss to find Lyza. Reg also decides to accompany her since he believes ...read more Upon reading the note, Riko decides to descend into the Abyss to find Lyza. Reg also decides to accompany her since he believes that he will find answers to both his own identity and his lost memories in the Abyss. However, Nat openly opposes their plan, since he knows that if Riko goes to the bottom of the Abyss, the Curse of the Abyss will make her unable to return to the surface ever again. He then points out Lyza is most likely dead since it would be impossible for even a White Whistle to survive in the Abyss for ten years, which angers Riko. The next night, Riko sneaks out of the orphanage to begin her journey. Reg stays behind temporarily to convince Nat to come say goodbye, but finds he is missing. After seemingly bluffing a suspicious Jirou, Reg reunites with Riko and they are met by Nat, who regrets the hurtful things he said to Riko and agrees to guide them to a secret entry point into the Abyss. After saying their goodbyes, Riko and Reg descend into the Abyss. show less
Riko and Reg manage to descend deep down into the first layer of the Abyss. Reg then remembers that Jirou slipped a letter into ...read more Riko and Reg manage to descend deep down into the first layer of the Abyss. Reg then remembers that Jirou slipped a letter into his backpack and reads it. The letter contains a copy of vital information about the Abyss, as well as a note from Jirou warning the two that he will pursue them at dawn. Riko concludes that Jirou is testing them, and if they can reach the second layer without getting caught, he will stop chasing them. The two continue down to the second layer when they are intercepted by Habo. He tells them that Nat and Shiggy requested that he escort the two of them to the Seeker Camp in the second layer. While grateful, Riko declines Habo's help since she and Reg want to reach the second layer on their own. Habo informs them that the guardian of the Seeker Camp is Ozen the Immovable, a White Whistle who helped Lyza transport the infant Riko to the surface. He also warns the two to be wary of Ozen before saying his farewells. Riko and Reg then reach the second layer, the Forest of Temptation. show less
As Riko and Reg proceed through the second layer, they encounter a corpse weeper, a large carnivorous bird that can mimic the ...read more As Riko and Reg proceed through the second layer, they encounter a corpse weeper, a large carnivorous bird that can mimic the cries of help from its prey. Riko is captured by a corpse weeper and flown to its nest to be fed to its chicks. In desperation, Reg activates an energy cannon within his hand that destroys the corpse weeper and large swathe of the surrounding landscape. Riko is saved, and she is greatly impressed by Reg's energy cannon, which she dubs the "Incinerator", but Reg then passes out from the strain of using the weapon. After Reg wakes up, he and Riko proceed to the Inverted Forest at the bottom of the second layer, where the Seeker Camp is located, chased by monkey-like creatures. As they approach the Seeker Camp, Reg's extendable arms are seized by its guardian, Ozen the Immovable. show less
Riko and Reg are allowed inside the Seeker Camp, where they finally meet Ozen as well as her apprentice, Marulk. Riko thanks ...read more Riko and Reg are allowed inside the Seeker Camp, where they finally meet Ozen as well as her apprentice, Marulk. Riko thanks Ozen for helping carrying her out of the Abyss as a child, though Ozen darkly notes with amusement that she had considered many times just leaving Riko behind. Ozen allows Riko and Reg to stay the night at the Seeker Camp, and they quickly befriend Marulk, who wishes that they stay for a while longer so they can cave raid together. However, Riko reluctantly declines, as she wants to continue her journey to find Lyza. That night, Riko leaves her room to look for the bathroom and encounters a strange creature. Terrified, Riko flees back to her room. The next morning, Ozen tells Riko and Reg that she knows about the creature, and leads them to her chamber to explain it. Along the way, she tells Riko that Lyza is dead, as she recovered the letter from a grave in the fourth layer. In addition, the note Riko received telling her to go to the bottom of the Abyss was not written by Lyza. They then arrive at Ozen's chamber, where Riko sees the Curse Warding Box, the Relic that protected her as an infant. show less
Ozen reveals that the Curse Warding Box has the power to temporarily revive the dead and the monster Riko saw was a lump of meat ...read more Ozen reveals that the Curse Warding Box has the power to temporarily revive the dead and the monster Riko saw was a lump of meat she had placed in there, returning to life before dying again a few hours later. She also reveals that Riko was dead when Lyza delivered her and she was revived by the powers of the box as well, although she has no idea how much time until the effects will wear off and she will die again. Ozen then starts attacking Reg, who attempts to defeat her, but falls unconscious after attempting, and failing to use Incinerator against her. After he awakens, Ozen reveals that she was testing them to check if they can survive by themselves in the Abyss and decides to train them, just like she once did with Lyza. She also reveals that the grave she found was in fact empty, implying that Lyza may still be alive. After Reg recovers, Ozen tasks him and Riko to survive in a nearby forest for 10 days without returning as part of their training. She warns them that Reg's Incinerator must only be used as a last resort because after Reg fires it, he will collapse within minutes and remain unconscious for approximately 2 hours, leaving them defenseless. Ozen then leaves Reg and Riko to fend for themselves. show less
Despite some setbacks, Riko and Reg successfully complete their survival training and return to the camp, where Ozen reveals to ...read more Despite some setbacks, Riko and Reg successfully complete their survival training and return to the camp, where Ozen reveals to them that the note written by Lyza was done in some kind of fabric that is too strong for even her to tear apart, another sign that she must be indeed alive. Before sending them away, Ozen gives Riko the "Everlasting Pickaxe", Lyza's weapon that she salvaged from the Fourth Layer, warning them that it could be used as an alternative to Incinerator, but may have only a few uses left before breaking, and shares with them the secrets of the Abyss accessible only to the White Whistles, while instructing them to avoid the other White Whistles that are currently exploring the Fifth Layer, as they could be a threat to them. Ozen then reminisces about a promise she made to Lyza to help Riko find her if they ever crossed paths. Riko then bids farewell to Marluk and the other residents of the camp before setting for the Third Layer of the Abyss, the "Great Fault". show less
Riko and Reg begin climbing down the Great Fault, using a network of caves to avoid the flying predators that inhabit the layer. ...read more Riko and Reg begin climbing down the Great Fault, using a network of caves to avoid the flying predators that inhabit the layer. However, they accidentally stumble into a madokajack nest and Reg is forced to use his Incinerator to kill the madokajack. After narrowly escaping the crimson splitjaw that had previously been wounded by the Incinerator, Reg falls unconscious, leaving Riko to fend for herself. As Riko drags Reg along, she is lured in and swallowed by an amakagame and forced to cut her way out of its stomach. Riko is then forced to flee a swarm of neritantans and finds herself in a cave with an upward slope. With no other choice, Riko heads up the slope, suffering the effects of the Curse and experiencing various hallucinations. After reaching the top of the cave, Riko realizes how important Reg is to her as both a friend and protector. Reg wakes up just as the crimson splitjaw returns and he is able to fight it and chase it off. After making camp, Reg realizes that he can now see the Fourth Layer, the "Goblet of Giants". show less
Riko and Reg begin their trek further down the Goblet of Giants, but as they press onward, they sense a presence moving along ...read more Riko and Reg begin their trek further down the Goblet of Giants, but as they press onward, they sense a presence moving along with them as they speak. They continue descending until they are confronted by an orbed piercer, and Reg prepares to face it until Riko reveals its spines are capable of piercing steel and poisoning their victims, putting Reg's life in danger as well. They attempt to escape, but the monster is able to read their movements and stop them, knocking Lyza's pickaxe out of their grasp and removing any means of defending themselves. Reg tries to stop the following attack with a scaled umbrella, but the spines pierce through not only the umbrella, but Riko's hand as well, injecting lethal poison in her system, forcing Reg to escape with her by ascending. This unfortunately results in Riko suffering the Fourth Layer's Curse: bleeding from every orifice. Coupled with the poison, Riko hallucinates as well, and she urges Reg to sever her arm to prevent the poison from going further. Though hesitant, he complies, but mid-way through the process, Riko stops breathing, and Reg, fearing the worst, falls into despair until a mysterious being tells him to remain calm and perform CPR, getting Riko breathing once more. They retreat into the hideout of the being, who reveals themselves as Nanachi. show less
Continuing from last episode, Reg takes Riko to the hideout of Nanachi, who begins to work on patching up Riko. Reg is ...read more Continuing from last episode, Reg takes Riko to the hideout of Nanachi, who begins to work on patching up Riko. Reg is introduced to Mitty, a creature living with Nanachi, who reveals themselves and Mitty as Hollows: cave raiders who ascended from the Sixth Layer and lost their humanity as a result of the Curse, though Nanachi deems themselves proof of surviving the Sixth Layer and retaining their humanity. They send Reg off to fetch ingredients to heal Riko (as well as make Nanachi's dinner), and as he is out, Nanachi seems to recognize Lyza's white whistle. After fetching the ingredients, Reg is sent to clean Riko's blood urine stained clothes at a riverbank behind Nanachi's hideout, and there a memory resurfaces of him standing by a gravestone with Lyza's Blaze Reap in the ground. While Riko is left alone, Mitty begins to eye her. show less
Back in Orth, Kiyui has sudden fallen ill on his birthday, following a mysterious trend called the "Birthday Death ...read more Back in Orth, Kiyui has sudden fallen ill on his birthday, following a mysterious trend called the "Birthday Death Disease" which has begun to plague the town. Jirou takes him to a caravan fleet offshore for medical treatment when Kiyui's symptoms suddenly disappear, and a doctor muses that it may have something to do with the Curse of the Abyss. Back in the Abyss, Nanachi assures Reg that Mitty will not harm Riko, and she apparently has taken a liking to her. Reg then convinces Nanachi to teach him about the true nature of the Curse. Nanachi reveals the Curse is all around them in the air, and moves along with them. Many of the Abyss monsters such as the orb piercer can predict the future because they can see the Curse and predict their prey's actions based on it. Nanachi sends Reg out to train, and he comes across another cave raider being attacked by the orb piercer. Reg intervenes and thanks to Nanachi's directions, is able to chase off the orb piercer with his Incinerator. After leaving a message with the cave raider to tell Jirou that he and Riko are okay, Reg reunites with Nanachi, who requests that Reg kill Mitty for them. show less
While carrying the unconscious Reg back home, Nanachi remembers when several children, including Mitty and them, were taken in ...read more While carrying the unconscious Reg back home, Nanachi remembers when several children, including Mitty and them, were taken in by the White Whistle Bondrewd to his base deep in the Abyss, unaware that they were to be used for his experiments. In one of them, Nanachi and Mitty were sent together to the sixth layer and afflicted by the Curse of the Abyss upon being taken back, leading to their current appearances. After Mitty, who was turned into an immortal creature, was unsuccessfully killed several times by Bondrewd, Nanachi decided to flee with her. After considering Nanachi's request, Reg decides to accept it, and Nanachi bids farewell to Mitty before Reg destroys her completely with the Incinerator. Some time later, Riko awakens, but has lost most of her left hand's movements. Riko and Reg then asks Nanachi to join their quest to meet Lyza, and they agree. After sending a message to the surface that is received by Shiggy and Nat, Riko, Reg and Nanachi make their preparations before leaving to the fifth layer. At the same place Nanachi fled from, Bondrewd discovers that Mitty's life signature disappeared, realizing that Nanachi managed to somehow kill her, and is eager to meet Nanachi again. show less