The universe begins with Demon Slayer: Kimetsu no Yaiba

The days that followed were basically like this. Bai Yu would learn swordsmanship and sword skills from Rentaki Sago every day, while Tanjiro was doing his physical strengthening training on the side. When it's time for dinner, Tanjiro will go to the designated place to catch raw fish and come back.

Tanjiro's compulsory task every night is to run back to the cabin from Mt. Saagiri.

Although this project does not sound difficult, according to Tanjiro's own account, there were many traps set up by Nintaki Sa on the mountain.

Moreover, the location is changing every day, and as Tanjiro becomes more and more comfortable in water, the nature of the trap gradually changes, from being a simple containment to one that wants to kill Tanjiro.

From the beginning, Tanjiro could only clean up the mess left by Shiroha and Kintakisa after their last dinner, but gradually he was able to eat a few mouthfuls of leftover soup, and then he was able to come back in time for the middle of dinner. In the end, I was able to return to the cabin before dinner preparations started.

Every night, Tanjiro had the habit of talking and writing diary with Nezuko, while Bai Yu lay on his sleeping place, staring at the ceiling in a daze.

After Tanjiro was able to avoid all traps, Tanjiro also began to formally learn the basics of swordsmanship - swinging a sword.

As Tanjiro grows up, there are more and more things he needs to learn. But Bai Yu has been exploring the way of swordsmanship and the Ten Forms of Water taught to him by the old man.

Compared to Tanjiro, Bai Yu has much less to learn. For example, Tanjiro has to practice physical skills every day, but Bai Yu doesn't have to practice.

During these long days, Tanjiro's sister Nezuko has been in a coma. As for why Nezuko has been in a coma, Nintaki Sakonji can't give a reasonable explanation.

Half a year later, Nintaki Sago officially taught Tanjiro the key and essence of the water breathing method.

"Tanjiro, today I am going to teach you the water breathing method. You must listen carefully!" Nintaki Sakonji said to Tanjiro very seriously.

"Yes, master!" Tanjiro immediately became serious.

Bai Yu stood quietly beside Tanjiro without saying anything more.

"The breathing method is to allow oxygen to spread to every cell in the body through conscious long-term breathing. This can improve the body's natural healing power, as well as the body's strength and response. This kind of breathing is called concentrated breathing!"

"The breathing of water is to maintain a specific frequency of breathing on the basis of concentrated breathing. At a specific frequency, the rhythm of water will be produced. This is the breathing of water. The same is true for other breathings. They all belong to My own rhythm.”

——"Tanjiro, now relax your upper body, stabilize your lower body, and start breathing."

Nintaki Sakonji changed his tone and said to Tanjiro.

Hearing this, Tanjiro began to try to breathe according to Nintaki Sakonji's instructions.

As soon as he took a breath, Tanjiro's expression suddenly turned painful and he screamed.

In a blink of an eye, it turned out that it was Nai Taki Sakonji who hit Tanjiro in the abdomen with his palm.

"No, you must concentrate on breathing. You must use your Dantian to inhale the oxygen, not just rely on your nose. The nose is just a channel for oxygen to flow in."

"One more time, Qi sinks into the Dantian ~ spreading oxygen to every cell in the body through the Dantian."

"Yes, Master!" Tanjiro responded again, and then tried again.

"Ah~ah~ah~"

What happened next was Tanjiro screaming as his attempts failed again and again.