Zenitsu stood outside, listening to the voices inside. There were two people in the room.
One was Grandfather, Jigoro Kuwajima.
The other was...
Zenitsu's expression slowly changed. His hearing was an extraordinary sense on par with Tanjiro's nose. Not only could he clearly hear distant or faint sounds, he could even distinguish the differences in breathing between humans and other creatures.
"Old man! Do you know how many people have looked down on me because I can't use [First Form]?! Even that brat Zenitsu mastered [First Form]. There's no reason I shouldn't be able to learn it. You must have done something!"
"What are you saying? How could I possibly treat you and Zenitsu differently? Zenitsu is a student I'm proud of, and so are you..."
"You expect me to believe that?!"
Thunder Breathing had six different sword techniques. Not only were there few of them, their structure was also rather different from that of other breathing styles.
For example, Flame Breathing and Water Breathing had their most refined techniques in their final forms. Thunder Breathing was the exact opposite: its very first form was its core.
The voices inside grew increasingly heated. Zenitsu could no longer hold back. He pushed open the unlocked door and stared into the room with his teeth clenched.
His grandfather, Jigoro Kuwajima, had fallen to the floor. Standing before him was Zenitsu's senior fellow student, Kaigaku.
"Kaigaku! How the hell did you turn into a demon?!" Zenitsu roared furiously at the senior he had once respected.
The Kaigaku before his eyes no longer looked human. Demonic fangs protruded from his mouth, his ears were pointed like a bat's, and his skin was deathly pale. Black, tiger-stripe-like demonic markings covered his face.
Shock and fury surged through Zenitsu at the sight. Had Chinatsu seen it,