Ep 17. You Must Master a Single Thing

In Episode 17 of Demon Slayer Kimetsu No Yaiba, entitled "You Must Master a Single Thing," Tanjiro trains with the Water Hashira, Giyu, in order to master a new technique that will help him defeat demons. The episode begins with Tanjiro struggling to grasp the concept of "total concentration constant." Giyu explains that it is the foundation of all sword techniques, but Tanjiro is having a difficult time understanding it.

Giyu tells Tanjiro that he must master a single thing before he can move on to more advanced techniques. He then demonstrates the power of the Water Breathing technique by slicing a boulder in half with his sword. Tanjiro is in awe of Giyu's skill and realizes that he has a long way to go before he can master Water Breathing.

The training begins with Tanjiro practicing his breathing technique under the guidance of Giyu. He must learn to control his breathing in order to enhance the power of his sword. Tanjiro struggles at first, but he is determined to improve. His hard work pays off when he finally achieves the "total concentration constant" and is able to slice a rock in half with his sword.

However, Tanjiro soon discovers that he has only scratched the surface of the Water Breathing technique. Giyu shows him the five different forms of Water Breathing, each with its own unique movements and abilities. Tanjiro is overwhelmed by the complexity of the technique but is determined to master it.

The episode then flashes back to when Tanjiro was training with his master, Urokodaki. Urokodaki taught Tanjiro the basics of sword fighting and Water Breathing, but Tanjiro struggled to use it effectively against stronger demons. Urokodaki then reveals that Tanjiro's sister, Nezuko, may hold the key to defeating demons.

Tanjiro returns to the present, determined to master Water Breathing and unlock Nezuko's potential. He continues his training with Giyu and gradually becomes more skilled at the technique. However, his progress is put to the test when a powerful demon attacks them.

Tanjiro and Giyu team up to take down the demon, with Tanjiro using Water Breathing to enhance the power of his sword strikes. The demon proves to be a formidable opponent, but Tanjiro's training pays off when he is finally able to land a decisive blow.

The episode ends with Tanjiro realizing that he still has a long way to go before he can truly master Water Breathing. However, he is hopeful that with more training and dedication, he will be able to defeat more powerful demons and protect his loved ones.