Gachiakuta episode 4: Riyo's Vital Instrument is revealed, as a new threat for Rudo lurks in the shadows

Gachiakuta episode 4, titled Cleaners HQ, was released on Sunday, August 3, 2025. The episode showcased Riyo in all her glory, as she demonstrated the powers of her Vital Instrument to fight against a horde of Trash Beasts.

Additionally, the episode saw Rudo observe how the Cleaners work as an apprentice. Gachiakuta episode 4 introduced more Cleaners and revealed the various categories in the organization. Furthermore, the episode witnessed an exhilarating ending.

Disclaimer: This article contains spoilers from Gachiakuta episode 4.

Gachiakuta episode 4: Rudo visits the Cleaners HQ and joins a mission as an apprentice

Zanka, Riyo, and Rudo (Image via Bones Film)

Picking up the events from the previous episode, Gachiakuta episode 4 begins with Enjin, Riyo, Rudo, and Zanka arriving at the Cleaners' HQ. After entering the premises, Rudo meets the Cleaners' receptionist, Semiu, eating food at the desk. Semiu states that she has heard about Rudo from Enjin and can't wait to see his potential.

According to Gachiakuta episode 4, Semiu's Vital Instruments, i.e., her glasses, enable her to see a person's true nature. She demonstrates her Giver abilities on Rudo and confronts a static vision. Although Semiu flinches at the sight and senses something ominous, he avoids talking about it.

Semiu, as seen in the episode (Image via Bones Film)

Rather, Semiu tells Enjin that the boy has incredible harmony with his Vital Instrument. However, she acknowledges that Rudo needs to learn how to control his abilities, as they aren't stable yet. Later, she notes that Rudo has a turd on his neck. Enjin laughs and realizes why so many flies are swarming them.

Afterward, Enjin bids goodbye to Semiu, saying that he needs to see the boss. On the way, Enjin explains to Rudo the system at the Cleaners. According to Enjin in Gachiakuta episode 4, the Cleaners HQ is composed of around 100, who are categorized into combatants, support, and guards. He takes Rudo to a room full of Cleaners, but closes the door soon after.

Following this, in Gachiakuta episode 4, Enjin and Rudo arrive at the boss's room. The former warns the boy not to ask the boss about what Vital Instrument he has. As Enjin opens the door, he sees Semiu inside, who informs him that the boss has gone on a business trip and won't be back for a while.

Rudo becomes visibly angry at Enjin, wanting to meet the boss. At this moment, in Gachiakuta episode 4, Riyo enters the room and suggests Rudo join the Cleaners on an operation as an "apprentice." She thinks it will be good for the boy to observe how things are tackled at the Cleaners. Moreover, she also wants to know more about Rudo.

Thus begins Rudo's observation field trip, as he joins Riyo and others on a comparatively "easier" mission. While it's an easy job, Riyo advises Rudo to stay alert and watch closely how the Cleaners work. A flashback scene in Gachiakuta episode 4 reveals the minutes of the mission.

According to Semiu, the residents of a small town near the Polluted Zone have spotted Trash Beasts approaching the barricade. As such, they need a Cleaner to exterminate those Trash Beasts from infiltrating the town. When Rudo asks what a Polluted Zone is, Semiu explains that the Ground is divided primarily into two areas: Safe Zones and Polluted Zones.

Safe Zones are fit for human habitation, while the Polluted Zones are primarily inhabited by the Trash Beasts and heaps of garbage. Semiu further explains that Rudo fell into one of the most dangerous polluted zones called the No Man's Land. According to Gachiakuta episode 4, people need to wear masks to survive in the No Man's Land and the polluted zones.

Gachiakuta episode 4: Riyo expertly showcases her Vital Instrument

Afterward, Gachiakuta episode 4 cuts to Rudo observing a pile of garbage during his mission. He suddenly realizes that the Ground is enriched with treasures. Following this, Rudo asks Riyo about some of the other cleaners. Riyo says that they are called Supporters. Although the Supporters don't have the abilities of a Giver, they are valuable colleagues who lend support to the Cleaners.

At this moment, in Gachiakuta episode 4, a Supporter introduces himself as Gris and shakes hands with Rudo. Interestingly, Rudo experiences pain from the man's strong grip. Riyo notes that Gris's strong grip can smash a Trash Beast's armor. Their casual conversation is cut short as a Trash Beast is spotted. Rudo is surprised by the sheer number of Trash Beasts, but Riyo assures him that it will be fine.

Furthermore, Rudo senses that the Trash Beasts are similar to the way animals behave. Soon, they break through the barrier and approach the Cleaners. Once a giant Trash Beast gets closer, Riyo observes the creature and remarks how cool it is. She mentions that strong opponents fire her up.

Following this, Gachiakuta episode 4 showcases Riyo's might, as she demonstrates her Vital Instrument, a pair of scissors, to destroy several small Trash Beasts. One of the Supporters explains that Riyo's Vital Instrument is called The Ripper. Normally, scissors are used with the hands.

However, when Riyo transforms her scissors into a weapon, she uses them with her feet. At this moment, one of the supporters tells Riyo not to slack off, even though he is only observing. Just then, a Supporter exterminates a Trash Beast behind Rudo.

Riyo's Vital Instrument in Gachiakuta episode 4 (Image via Bones Film)

Following that, in Gachiakuta episode 4, Rudo watches in awe how everyone in the Cleaners work together as a team, even though some of them don't have Giver abilities. Meanwhile, Riyo takes care of several smaller Trash Beasts and goes after the big one. At this moment, a Supporter named Follo gets caught up by a Trash Beast that Riyo thought she had defeated.

However, he is luckily saved by Rudo, who activates his Vital Instrument with a stick. The stick creates a web of patterns around the beast. Suddenly, Rudo grapples with an unprecedented thought: He doesn't know how to use his powers.

Just as the Trash Beast is about to kill Rudo, Riyo arrives on time and saves the boy. The other Supporter, Follo, apologizes for letting his guard down and asks Riyo if she has exterminated the Trash Beasts. Riyo replies that she did cut the big one in half, but it's not disappearing.

Gachiakuta episode 4: A major threat searches for Rudo

Riyo showcases his powers (Image via Bones Film)

Gris, Riyo, and other Cleaners continue the battle against the giant Trash Beast while realizing that it's unaffected by their Vital Instrument. Riyo comments that a Trash Beast's vital points are the same as those of a living creature. With that logic, her cutting it in half should have worked. Unfazed by the situation, Riyo presses on and decides to keep cutting it til it stops moving.

Meanwhile, Rudo wonders if there's a way he can help. On the other hand, Riyo continues to cut down the beast. Suddenly, she notices something glowing inside it. The gigantic Trash Beast then smashes the ground, causing Rudo to fall into one of the cracks. As he falls, Rudo thinks about how he can avenge Regto's death when he can't even use his Vital Instrument.

Gris, as seen in Gachiakuta episode 4 (Image via Bones Film)

At this moment, Gris catches Rudo and pulls him up. He motivates him and begins to run to a safe place. Meanwhile, the Trash Beast shrieks as Riyo attacks its weak spot. Eventually, she pierces through the beast with her Vital Instrument. After exterminating the beast, Riyo shows a piece of an item he found from the beast.

Apparently, the Trash Beast was empowered by a Vital Instrument. Elsewhere, one of the human traffickers from before appears confused and finds himself in an unknown place. He remembers facing Rudo, a "Sphereite," earlier. Just then, he sees a mysterious person sitting close to him. Gachiakuta episode 4 ends with the mysterious person asking the man about the Sphereite's location.

Conclusion

The mysterious figure in Gachiakuta episode 4 ending (Image via Bones Film)

Produced by Bones Film, Gachiakuta episode 4 witnessed Riyo in full motion, as she demonstrated her Vital Instrument, the Ripper. Additionally, the episode added layers of mystery to the narrative. It was revealed that someone or a group was responsible for empowering Trash Beasts with Vital Instruments. Furthermore, the episode saw Rudo experience a minor setback as a Giver.