Light Novel Volume 10/Synopsis

Prologue: The Spirit Tortoise's Barrier
Naofumi and his party transported back to the previous world, and just as they arrived, the Spirit Tortoise's energy they retrieved dissolved into the atmosphere. Naturally, as a foreign entity, Raph-chan power-ups has been reset and the other's level went back to normal. The queen of Melromarc arrived aboard a carriage and along with the soldiers, gave a saltatory bow. After a brief conversation, Naofumi and co. boarded a carriage and headed for the castle.

Chapter 1: The Seven Star Staff Hero
Naifumi found out that the time in Kizuna's world passed differently from Raphtalia's world. Arrived at Melromarc, Naofumi talks about the countdown for the next Wave and various things regarding the other world and its heroes. Naofumi suggests the Queen muster the Seven Star and Holy Heroes' power and knowledge to handle the Waves. The Queen only accepted to gather the Seven Star Heroes due to the three Heroes has fled. Naofumi and the Queen also discussed about the aftermath of the Spirit Tortoise's battle and its effect to the coalition army. Naofumi then asked the Queen for a territory to build a private army to fight the Waves. The Seaetto territory is chosen by Naofumi, and he is given the title of Count by the Queen. After the ceremony, the Queen introduces Trash as one of the Seven Star Heroes. Due to his refusal to cooperate, the Queen planned to torture Trash to reveal his way of power-up.

Chapter 2: Whereabouts of the Slaves
Naofumi headed to the Slave Trader but interrupted by the Queen. She explains that before Naofumi arrived, she proclaimed an order to release slaves from Seaetto in Melromarc, but the slaves apparently sold off in anticipation of the proclamation. Currently, the Slave Trader is doing an investigation of the Seaetto slaves' whereabout. Naofumi proceeds to visit the Slave Trader and bought a few slaves. While the Slave Trader is taking care of formalities regarding the slaves, Naofumi went out to visit another place.

Chapter 3: Acquaintances
Visiting the old guy's weapon shop. A sword for Rishia that Naofumi ordered long ago has finished and the old guy is being asked by Naofumi to take apprentice, for his new territory's blacksmith. Naofumi also asked the old guy to take a look at his party's armors and outfit from Kizuna's world to see if it can be fixed.

Chapter 4: E Float Shield
Returned to the castle to take some equipment from the storeroom. The Queen has rounded up Spirit Tortoise's materials at the training grounds for Naofumi. When Naofumi takes a look at it, the materials are absorbed by the shield, seemingly of their own accord and unlocked various shields and a skill called E Float Shield. Naofumi then headed to the Slave Trader again to pick the slaves up and buy monster eggs. Naofumi cooks a meal for the party, new slaves, the Slave Trader, and his assistant. After the meal, Naofumi with the Slave Trader, his assistant and the of his party including the new slaves departing for the new territory.

Chapter 5: The Seaetto Territory
Naofumi and his troupe stop by a neighboring town to meet Eclair. Assisted by Granny and Melty, Eclair is rebuilding the town. Keel and three other survivors of Lurolona village are there as well. Considering the project's lack of tangible progress, Naofumi criticized and give Eclair an explanation regarding the government. Naofumi tells Eclair that he will rebuild the neighboring village and leave the towns rebuilding to her. The Slave Trader is ordered to apply slave curse to the three Demi-Humans but they resisted it. After some talk from Naofumi and his friends, Keel, and Raphtalia, they are convinced to be slaves and the Slave Trader proceeds with the slave curse ceremony.

Chapter 6: Feeding the Herd
The first day in the village is spent in cleaning up the wreckage of the destroyed buildings, leveling up the slaves. Melromarc soldiers also help to fix the buildings. Between activities, Naofumi cooks meals, but the slaves need more than he anticipated. By the end of the day, at least one house has been fixed and another have its roof installed. In the second day, due to the previous day's deficit flow of food supplies, Naofumi ordered the leveling-up troupe to make up for losses with hunting.

Chapter 7: Employing the Bioplant
Naofumi uses the Bio Plant to lessen his burden in case the slaves get hungry in times he can't cook or not around. He also ordered them to manage the plant. The slaves did well in leveling up.

Chapter 8: Children of the Sea
Since Raphtalia and other Lurolona Demi-humans mentioned Sadeena, Naofumi asked Raphtalia about her. Raphtalia and Keel tell Naofumi about Sadeena and her strength. After the talk, Naofumi takes the slaves to the ocean. At the beach, Naofumi noticed that Keel is actually a girl. Back to the village, Naofumi hatched the six eggs he bought from the Slave Trader a while ago. A Filolial, two Caterpilands, and three Dunes monsters are hatched. Naofumi tells everyone that he'll be forming divisions to take care of the cooking and other tasks. After the initial personnel distribution, he taught them how to do their task.

Chapter 9: Hanging Out the Shield
Naofumi went peddling to sell medicines. The slave trader informed that some of the village's former inhabitants are likely at Zeltoble. Naofumi set out to Zeltoble with Filo and Raph-chan.

Chapter 10: Zeltoble
Naofumi arrived at Zeltoble and visit an underground slave market. After the Slave Trader explaining the situation regarding the slave price, they went to an auction site. Bewildered by the price, Naofumi planning to earn money by participating in the Coliseum.

Chapter 11: Slave Hunters
Naofumi and the party went back to Seaetto and find out that the village is under attack by slave hunters. Raphtalia and Keel, with aid of Naofumi, defeated the hunter boss. The rest of the hunters then immediately defeated. To amass a large amount of money for the wager in the Coliseum, Naofumi sold the captured hunters to Siltvelt.

Chapter 12: The Department Store
Naofumi asked about the tournament and ordered the Slave Trader to register him with Raphtalia and Filo in the team tournament. Because there are an upcoming match and an auction is held at the same time, Naofumi ordered Raphtalia to observe the auction while he went to observe a match later. Naofumi and co. went to a department store to look at weapons and armors where he met the accessory dealer back from his peddling days. Proceeding to the weapon and armory section, Naofumi and Raphtalia copied a few shields and katanas they don't have. No weapon or armor was worth buying there, so they went back to the underground slave market.

Chapter 13: The Underground Coliseum
By himself, Naofumi takes a peek at the coliseum battle. A drinking contest has happened near the fight. The winner of the drinking contest, Nadia, approached Naofumi and predicted the outcome of a coliseum fight. The fight ended as Nadia has predicted. Naofumi assumed that Nadia is familiar with the Coliseum, asked her various things about it.

Chapter 14: Ring Name
Naofumi and the party used an alias and wearing masks for the tournament to avoid attention. The first match is started, the opponent team is Topak Family, Naofumi's team won swiftly. The second match is against a team solely made of three monsters and again won swiftly. After the matches, Naofumi sent Filo back to Seatto, Raphtalia is sent to monitor the Lurolona slave auction winners. Rishia and Raph-chan are gathering information regarding coliseum fighters.

Chapter 15: Surprise Attacks and Conspiracies
Naofumi headed back to the tavern where he met Nadia and surprisingly she noticed that Naofumi was participated in the tournament, despite the effort to hide his identity. Nadia brings Naofumi for a night stroll but they are ambushed by mercenaries. Nadia defeated the mercenaries swiftly and pointed out that these ambushes was the reason why some participants didn't appear in the tournament. Nadia told Naofumi to give up if they happened to fight in the tournament, then they went separate ways. After gathering information regarding the participants, Rishia reported that Nadia is an opponent they should wary of.

Chapter 16: Nadia
Due to the increased opponent's absence, Naofumi won by default for the next several days and reached the semifinals against Nadia. Nadia fought so well, even capable of canceling Naofumi's Aura buff and bested Raph. The arena then altered by the spectators to Nadia's favor. The spectator's interference made the fight went back and forth but in the end Naofumi's party cornered Nadia. Nadia gets serious and transformed into her beast form. When Nadia preparing an attack, Raphtalia just stood in a daze. Naofumi moves to protect Raphtalia, and then she uttered "Sadeena."

Chapter 17: Farce
Nadia suddenly halted her attack. Raphtalia and Nadia conversed and recognized each other. Nadia suggests them to pretend to continue the battle while explaining each other's situation. After Raphtalia and Filo staged an apparently devastating combo, Nadia admits defeat.

Chapter 18: Exhibition Match
Right after the match, the organizers forced Naofumi and Sadeena to team up and participate in an exhibition match under heavy handicap against Murder Pierrot who isn't even participating in the current tournament. With Filo's Humming Fairy skills and Sadeena's guide to using cooperative support magic, they managed to defeat Pierrot. Everyone was surprised to find that Pierrot's body was just wood and Pierrot appeared in another body. Pierrot talking to Naofumi and the party but the voice is disturbed by crackling and static noise, leaving an order to get stronger as the only perceptible message. After the talk, Murder Pierrot disappeared with an explosion. Naofumi is declared as the winner and headed back to the waiting room.

Chapter 19: Big Shots of the Underground
Sadeena went to confront her boss with Nao, followed by Rishia, Raph-chan, Acc dealer and Slave trader. With Acc dealer and Slave trader's backing, Nao proposed a deal to put Sadeena's bet to the next match so her previous contract can go on. In the next match, which is a throwaway, to begin with, Naofumi easily won.

Epilogue: Come-On
Naofumi obtained fifteen slaves and bring them to the village. Dialogues between Naofumi and the villagers, including Sadeena's attempt to claim him due to her defeat in a drinking contest.