Chapter 4

Tanjirou Diary - Part One (•) is the fourth chapter of Koyoharu Gotōge's Kimetsu no Yaiba.

Summary
The chapter begins with Urokodaki informing Tanjirou about the Demon Hunters, an organization that is composed of skilled swordsmen which are trained kill demons, despite not being acknowledged or officially recognized by the government.

He goes on to tell Tanjirou about some general information regarding demons, such as that they must eat humans in order to survive and have special abilities such as being able to regenerate when they're physically injured, the only way they can be destroyed is through the exposure to sunlight or by being decapitated with a specialized blade. Despite not knowing much about the origin of demons, the organization of demon hunters has continued to hunt demons with their mortal bodies, across a number of generations.

The scene pans to Urokodaki formally introducing his role as one of the many 'cultivators', which are individuals who train and furnish swordsmen with a variety of techniques and skills. He instructs Tanjirou that if anyone wants to enter the Demon Hunter Organization, they must first survive an event known as the Final Selection which is held at the Fujikasane Mountain. Urokodaki tells Tanjirou that he will be the one to decide if Tanjirou is qualified to participate in the Final Selection.

The chapter continues as told through Tanjirou's perspective, with his vigorous training of descending the mountain while avoiding traps along the way. His stamina has increased and he is able to detect smells much quicker. Soon after, Urokodaki teaches Tanjirou the way of the sword, recovery positions after getting thrown, and breathing techniques.

Meanwhile, Nezuko has fallen into a deep sleep, and it has been around half a year since they've arrived. The doctor came by to look at her, but the doctor finds nothing wrong with her. Worried that she will die soon, Tanjirou steels himself and trains harder.

One day, Urokodaki tells Tanjirou that he has nothing else to teach the boy. Taken aback, Tanjirou notes that a year has passed since their arrival. Urokodaki asks the boy to continue to improve upon his techniques and challenges the boy to split a huge rock in half to prove his worth in order to enter the Final Selection test. Tanjirou starts to panic as the task at hand seems impossible with his mere blade. From that day onwards, Urokodaki never taught Tanjirou anymore.

Another half year has passed. No matter how much Tanjirou practices, he was not able to split the rock. Feeling extremely disheartened, he yells in frustration, to which a voice asks him to shut up. The voice came from a person wearing a fox mask. Much to his surprise, Tanjirou observes that this fox masked person did not have a scent nor did Tanjirou notice where the person came from.

He then tells Tanjirou to shut up like a man and deal with it and subsequently exchanged blades with Tanjirou.

He quickly defeats Tanjirou and tells Tanjirou that he is not fit to be a man.

Characters in Order of Appearance

 * Tomioka Giyuu
 * Obanai Iguro
 * Kochou Shinobu
 * Urokodaki Sakonji
 * Kamado Tanjirou
 * Kamado Nezuko
 * Sabito