Haru accepts the dimensional chat invitation and is immediately branded Sis-Con. Four strangers appear: Gintoki, Tsunade, Yajima, and Kuroneko. They are all characters from anime worlds Haru remembers from his past life. When he reveals he knows their futures, the group dynamic shifts. Kuroneko uploads Yosuga no Sora to the chat, exposing Haru's most intimate secrets to everyone. The humiliation is absolute, but the power he gains is intoxicating. He learns Light Magic in a single night, healing wounds and bending light to become invisible. The chat becomes his lifeline and his curse, a place where he can grow stronger but also where his deepest vulnerabilities are laid bare. His sister Sora sleeps beside him, unaware that her brother has just become the anchor of a dimension-hopping collective.

Haru buys a cheap haunted house where three children were murdered. Inside, he encounters their ghosts, terrified shadows who beg him to find their older sister Yuri Nakamura. Using Light Magic, he purifies them, revealing their true forms as scared children. He tracks down Yuri, a kendo champion, and brings her to the house for a final reunion. The siblings say goodbye and ascend to heaven, leaving Yuri in tears. Haru comforts her, and she agrees to work at his future maid cafe. The experience deepens his understanding of his own power and his responsibility to those who cannot protect themselves. He also begins to realize that his light magic can heal not just bodies but also souls.

The group chat issues its first quest: stop Orochimaru from destroying Konoha. Haru, Gintoki, Yajima, and Kuroneko teleport to the Naruto world. They meet the Third Hokage, tour the village, and prepare for the Chunin Exam attack. During the chaos, Kuroneko is nearly killed by Kabuto, and Haru takes a kunai to the shoulder protecting her. He kills Kabuto with a light beam, his first human kill. Later, he uses a Solar Flare technique to blind Orochimaru, allowing the Hokage to capture him. The quest succeeds, and Haru receives Sticky Fingers, a Stand that lets him create zippers on any surface. He uses it to escape the hospital and train with his new power, realizing that he is no longer just a novelist but a warrior.

The second quest sends Haru alone to Impel Down to help Luffy rescue Ace. He infiltrates using invisibility and Sticky Fingers, fights alongside Luffy, Ivankov, and Crocodile, and uses his zipper power to create paths and shields. He defeats Moria in seconds and helps Whitebeard avoid betrayal. At the execution platform, he uses a zipper shield to block Akainu's magma and saves Ace. He invites Luffy to the group chat and returns home with a bounty of 385 million berries and a Haki training manual. The quest cements his reputation as a cunning, powerful ally and expands the chat with a pirate king in the making.