Arc 16The Swordsmith Village and Muzan
Teiichi stayed in the Swordsmith Village, helped Mitsuri pursue a stronger blade and pushed her to train without holding back. When he left to investigate possible traces of Doma, he encountered Muzan at a train station and fought him until Muzan escaped to the Infinity Castle.
- Teiichi commissioned a heavy, unusually resilient Nichirin Blade from Tetsumoto Homura, while Kotetsu began learning to help forge it.
- Kagaya Ubuyashiki ordered the Corps to gather information on suspected cults linked to Doma without confronting them, as reports from Kuroishi Village and Osaka revealed the Eternal Paradise Cult.
- Teiichi met Mitsuri in the Swordsmith Village and helped arrange a new flexible blade after Tecchin Tecchikawahara said he could no longer forge one to her specifications.
- Teiichi urged Mitsuri to stop limiting her strength to find a husband, and she trained against Yoriichi Type Zero and sparred with Teiichi.
- Mitsuri grew close to Teiichi during their training and meals, while Tengen Uzui arrived to have a more resilient Nichirin Blade forged.
- After a Kasugai Crow delivered a request to investigate possible traces of Doma, Teiichi left alone and recognized Muzan at the train station.
- Teiichi fought Muzan across the station, repeatedly cutting him and preventing him from attacking passengers until Muzan escaped into the Infinity Castle.
- Muzan’s roar briefly knocked Teiichi unconscious, and Teiichi recovered as his damaged Nichirin Blade broke apart, and Muzan collapsed in the Infinity Castle and cursed him.