Yuu Tōsaka, the adopted son of the Tōsaka family, later went to the Clock Tower for "advanced training." His original plan was for him to pursue a career as a magus after graduation... until he stumbled upon a game disc. After opening it, he entered the game's world and encountered Tiamat right at the start. [Quest: Fight alongside Tiamat] "Wait, why aren't you asking me to save Humanity?!" Yuu Tōsaka quickly discovered his blind spot, but he ultimately successfully completed the system quest and spent a wonderful time with Tiamat. ...After that, he journeyed through several different game arcs. In Britain, he was King Arthur's childhood sweetheart. During the Fourth Holy Grail War, he found a girl who adored him... her name was Sajo Aika. After finally completing the game, Yuu Tōsaka was about to put the disc away for safekeeping when, one sunny afternoon, the Heroic Spirits he had captured in the past arrived. The Knight King, Morgan the Fairy, Tiamat, the Root Princess... Looking at the unique Heroic Spirits before him, Tōsaka Yuu began to sweat profusely. "The Heroic Spirit I captured in the game... actually became real?!"

"After transmigrating into the Naruto world, I awakened the [Netherworld Livestream System]—a platform that connects to the Pure Land!

From that day on, the Pure Land gained a money-grubbing, scam-artist streamer...

...while the shinobi world inherited an unstoppable, flower-stealing demonic prodigy!*

During the Fourth Great Ninja War, when Kabuto unleashed the [Impure World Reincarnation] jutsu to summon fallen legends...

...the first thing the Edo Tensei zombies did wasn’t obeying Kabuto’s orders.

No—driven by sheer hatred, they defied the caster’s control and stormed off to hunt down that bastard streamer instead!

Kabuto: "What the hell?! Since when?!"

Itachi: "…Don’t tell me they’ve all mastered Izanami?"