The story begins with Rinto, a Tamer, arriving in the royal capital. Tamers are considered a low-tier adventurer class, often looked down upon because most people prefer to improve their own combat skills rather than rely on monsters. Rinto, however, embraces the Tamer path, motivated by the desire to have stronger beings fight for him so he can slack off. His only companion is Kyuruke, a creature that evolved from a slime, now resembling a feathered, horned being. Rinto, having achieved D-rank in his hometown of Fremel, aims to start his legendary journey in the capital.
His grand entrance is immediately disrupted by the forceful passage of a small, beast-eared girl named Birena, who is accompanied by a massive, bird-like monster. Birena, a renowned A-rank adventurer known as "Flash of Light," apologizes briefly before rushing into the adventurer's guild. Rinto learns from other adventurers that Birena is an exceptionally powerful solo player, capable of defeating A-rank monsters alone and likely of S-rank caliber herself. He also learns that she rejects all party invitations.
Rinto, after gathering information about the capital and Birena from a seasoned adventurer named Digurd, approaches the quest board. Birena spots him and apologizes again for the earlier collision, showing concern for his well-being. To Rinto's astonishment, she then proposes that he join her party. When Rinto questions her motives, she cryptically mentions his "good smell." He probes further, assuming she has goals like reaching S-rank, but Birena reveals she has already achieved S-rank. She offers to let him join her, and Rinto, overwhelmed by the offer from a top-ranked adventurer, accepts.
After completing guild registration, Rinto is confronted by a burly, scarred man named Giran, who accuses Rinto of using underhanded tactics to get Birena to join his party. Giran, a B-rank adventurer, believes he is more suitable to partner with Birena and demands Rinto hand her over. Rinto, unimpressed by Giran's arrogance and relying on Kyuruke's strength, dismisses him. Giran's subordinates attack, but Kyuruke easily repels them, revealing its strength and surprising Giran, who initially dismissed it as a mere slime. Rinto defeats Giran, who is left sprawled amidst a broken table. The guild master confirms Rinto will pay for the damages, and other adventurers note Rinto's surprising strength for a Fremel newcomer.
Later, Birena expresses her belief that Rinto possesses a special skill beyond simple taming, citing Kyuruke's unusual evolution. She suggests they visit an appraiser. During a lavish meal, Birena makes a shocking proposal: she wants Rinto to tame her. Rinto is taken aback, as taming demi-humans is unheard of and potentially taboo. Birena insists it's acceptable since she is proposing it and that it's not a slave contract, but rather based on trust. After some playful banter and a suggestive whisper from Birena, Rinto agrees. He successfully tames Birena, who feels a surge of power, while Rinto feels drained. They engage in further "training" sessions, with Birena's playful demeanor and Rinto's increasing bewilderment.
The next day, Rinto and Birena officially form a party, facing glares from other adventurers. Birena declares their next goal is to make their party S-rank. Another man, different from Giran, confronts them, belittling Rinto. Birena easily deflects his attack and swiftly defeats him, demonstrating her enhanced strength. She explains that Rinto's taming has significantly boosted her abilities.
Birena then takes Rinto to a dangerous volcanic region known as the Dragon's Nest, an A+-rank area, with the intention of having Rinto tame a dragon. Despite Rinto's protests about the danger and his D-rank, Birena is determined. They encounter an Earth Dragon, which Rinto, with Birena's assistance, manages to tame and names Gil. Birena reveals that Rinto's taming ability is extraordinary, capable of not only evolving monsters but also converting them into desired forms. She demonstrates this by causing a horn to grow on Birena, significantly increasing her power.
Their journey continues as they aim to assemble a full S-rank party. Birena proposes taming a Saintess, a powerful white mage and a symbol of the Divine Kingdom, which Rinto finds alarming due to the potential international repercussions. Birena, however, is undeterred, driven by her desire for adventure and Rinto's unique abilities. She also expresses interest in taming an Elf Queen and powerful demons.
During their travels, they are attacked by an S-rank monster, the Flame Emperor Wolf. Birena requests one minute from Rinto to prepare for battle. Rinto, with Kyuruke and Gil's help, manages to defend against the wolf's attacks while Birena gathers her strength. The chapter ends with Rinto realizing his own growth and the immense power at his disposal, as he and his companions face the formidable Flame Emperor Wolf.
