Recaps

Mu Yu grew stronger through the Tree Planting System and trained under Koshiro while helping Kuina and Zoro pursue their ambitions. After Terukawa attacked the Isshin Dojo and kidnapped Kuina, Mu Yu and Zoro tracked the pirates to Crescent Bay, where Mu Yu began fighting them.

• Mu Yu arrived in Shimotsuki Village, joined Isshin Dojo, and used the System to grow his physique and swordsmanship while training with Kuina and Zoro.
• Mu Yu defeated Zoro and encouraged Kuina to keep pursuing strength, then won powerful rewards that included Kanemoto and the Miyamoto Musashi Soul Tree.
• Mu Yu challenged Koshiro, lost, and endured a year of demanding training before Koshiro told him to train alone until he passed the final test.
• Mu Yu returned to the dojo and found Terukawa had attacked it and abducted Kuina after she fought his subordinate to protect the dojo signboard.
• Mu Yu treated the injured dojo members, then joined Zoro in pursuing Terukawa and retrieved Wado Ichimonji from Kuina’s room.
• At Crescent Bay, Mu Yu drew the pirates’ attention, killed Heng Er, and cut through Brecci’s hardened skin with a high-speed sword draw.

After saving Kuina and defeating Terukawa, Mu Yu left Shimotsuki Village and entered the Demon Slayer World. He hunted demons, helped several survivors, and trained Hasegawa before departing, leaving Hasegawa to meet Giyu Tomioka and Shinobu Kocho.

• Mu Yu defeated Terukawa, rescued Kuina and Zoro, and gained gravity powers and new abilities from the system.
• Kuina chose to eat the Asura Fruit, while Koshiro gave Mu Yu the right to pass on the dojo’s techniques and a Great Grade Sword named Myōō.
• Mu Yu bade farewell to Shimotsuki Village, drove off a Sea King with Conqueror’s Haki, and left the One Piece World.
• Mu Yu entered the Demon Slayer World, saved Kenichi Mitsushiro’s caravan from a demon, and stayed with the Mitsushiro family before giving them protective charms.
• Mu Yu helped Atsushi overcome a Centipede Demon and encouraged Hasegawa to live on after Shichiri Akihiko’s death.
• Mu Yu trained Hasegawa in Water Breathing until Hasegawa landed a counterattack, then gave him a life-saving bean and left.
• Hasegawa met Giyu Tomioka and Shinobu Kocho at Wisteria Crest House, described Mu Yu as the Water Hashira, and challenged Giyu to a fight.

Mu Yu defeated Jubei, met Inosuke, and drew the attention of Muzan and the Upper Ranks. He arrived at Ishibashi Town in time to save Kyojuro Rengoku from Akaza, but Akaza began regenerating after Mu Yu cut off his head.

• Giyu asked Kagaya Ubuyashiki to let him find Mu Yu and pass on his Water Hashira title, while Urokodaki received Giyu’s letter and Mu Yu’s training plan.
• Mu Yu and Shinobu Kocho investigated the Cherry Blossom Sea, where Mu Yu rescued Kenji and confronted the demon Jubei, who had killed his wife and become Ryota’s father.
• Mu Yu killed Jubei and absorbed Cherry Blossom Fall into his Swordsmanship Tree, then agreed to ask Shinobu to help Ryota join the Demon Slayer Corps.
• Muzan summoned the Lower Ranks, killed Mukago, and ordered Akaza and Doma to target the Hashira and Mu Yu.
• Mu Yu encountered Inosuke in the mountains, taught him about demons and the Demon Slayer Corps, and watched him choose to attend Final Selection at Wisteria Mountain.
• Kyojuro Rengoku defeated Bingye, the demon causing an epidemic in Ishibashi Town, but Akaza arrived and challenged the exhausted Flame Hashira.
• Kyojuro refused Akaza’s offer to become a demon and fought fiercely, but Akaza pierced his chest and broke his Nichirin Blade before Mu Yu intervened.
• Mu Yu rescued Kyojuro with a Senzu Bean and repeatedly evaded and wounded Akaza, eventually severing his limbs and head, but Akaza began regenerating.

Mu Yu defeated Akaza and Doma, rescued Shinobu, and earned the Hashira’s trust while revealing his strength and teaching them new techniques. As the Corps prepared to face Muzan, Mu Yu trained the wounded and received his newly forged Nichirin Blade, which he named Muzankiri.

• Mu Yu restored Akaza’s memories of Hakuji, Koyuki, and Keizo, and Hakuji rejected Muzan before reuniting with his loved ones.
• Hakuji warned Mu Yu that Doma had gone after Shinobu Kocho, so Mu Yu and Kyojuro Rengoku rushed to find her.
• Mu Yu overwhelmed Doma at the frozen lake, and Shinobu’s wisteria poison finished the Upper Rank Two demon.
• Mu Yu saved Shinobu as the lake collapsed, then healed Tengen Uzui and taught the Hashira Soru and other techniques.
• Mu Yu defended Nezuko before the Hashira, and Kagaya Ubuyashiki brought Tamayo to demonstrate that some demons could live without eating people.
• Mu Yu defeated all nine Hashira in a sparring match and offered to teach them Haki, while Shinobu volunteered to receive a Haki Seed.
• Mu Yu helped Mitsuri develop a new Love Breathing form and created Firefly Dance for Shinobu’s Insect Breathing.
• Mu Yu trained injured Demon Slayers at Butterfly Mansion and received his green Nichirin Blade, naming it Muzankiri and saying he would settle its name after killing Muzan Kibutsuji.