Otto's Peddling Record of Joy and Sorrow (オットーの、悲喜こもごも行商録 ) is a side story featured in Gekkan Comic Alive. It was later adapted in Re:Zero Tanpenshuu Volume 4.
After successful business in the city of Guineb, Otto prepares to continue his journey along with Verhoe. As Otto packs his merchandise into his dragon carriage, he is spotted by Guineb's representative Colin Lavril, who invites Otto to go to his own house to talk, and Otto reluctantly accepts. At Colin's house, Colin asks Otto to reveal the method he used to cross the mountains and arrive to Guineb, since the bridge to Guineb was broken; however, Otto refuses to tell him. Colin then introduces his son Arhim Lavril, and explains that Marone Lisbon, who Colin claims is his son's fiancée, was kidnapped by bandits hiding in the mountains, and they need to know his method so she can be rescued. Otto still refuses to reveal his method, but instead proposes to communicate the rescue appeal to the outside, in exchange for his future business receiving special treatment in Guineb.
Arhim, as ordered by Colin, accompanies Otto in the task. While they are travelling, Arhim asks Otto to stop the dragon carriage so he can go urinate, to which Otto complies. After a while, Arhim calls out to Otto, claiming he was stung by a bug and requires assistance. In order to help him, Otto goes to where Arhim is, and is made unconscious by an unknown force shortly after finding him.
When Otto wakes up, he finds himself bound by his arm in an underground jail cell, and is greeted by a woman who introduces herself as "number one" and refers to Otto as "number two". After talking to her, she reintroduces herself as Marone. Otto reaches the conclusion that he was kidnapped by the bandits too, which proves to be correct when the latter come to their cell. Otto asks the slave traders what happened to Verhoe, to which they answer that she now works for them. Otto then asks about Arhim, and the slave traders reveal that Arhim collaborates with them, and was the one who allowed Otto to be kidnapped. After the slave traders leave Otto and Marone alone, the two start to talk, and Marone reveals that Arhim was not actually her fiancé, and that she was also tricked and handed over to the slave traders by Arhim himself.
The next day, Otto and Marone are loaded into Otto's dragon carriage, which is led by Verhoe. Before that, Otto had already revealed he had a divine protection to avoid getting hurt; however, he revealed it as the "Divine Protection of Guidance" instead of his actual one, the "Divine Protection of Soul Language".
Before departure, Otto and Marone form an unknown agreement. When they finally depart, Otto is forced by the slave traders to show them how to cross the mountains (Arhim being the one who told them Otto knew), since they had plans to get far away from the city and form a new hideout. While they are travelling, Otto talks to one of the men and asks about Arhim, and the man reveals the details of their contract: Arhim would have to periodically hand over women and food to them, and in exchange the slave traders would stop messing around in Guineb. When the dragon carriage reaches a certain point in the path which Otto had previously told the driver to go through, Otto calls out to Marone, and she, as part of the aforementioned agreement she had made with Otto, clings to the carriage's inside with the help of her chains, and Otto does the same. In the next moment, Verhoe purposefully overturns the carriage, letting the slave traders fall off a precipice.
Later, in a hospital located in another city, Otto and Marone's injuries were treated. Otto tells her that an official investigation about Arhim's case, which will most likely lead to Arhim being arrested, will be done in Guineb. When Otto tells her that she has the choice of returning to Guineb, Marone blatantly refuses. Otto then gives her a bag full of money, which is said to be enough for a woman to find a new life by herself. Otto claims this money was given to them as a reward for stopping the slave traders' activities. Overcome with emotion, Marone embraces Otto and thanks him. She proceeds to ask Otto's real name, to which Otto replies that it is fine for her to keep calling him "number two".
After he separates from Marone, Otto continues his journey with Verhoe. It is revealed that Otto had partially lied to Marone, and that the money he gave her was not actually a reward, but his personal savings; and Verhoe scolds Otto for it. Verhoe jokes about Otto being naturally unlucky, but says she thinks it is completely fine that way, and she looks forward to Otto's dream (having his own store) being fulfilled.