Gabimaru loses his memory in Hell’s Paradise because he overuses his Tao , which literally damages his mind and alters his consciousness, leading to partial amnesia.

What actually happens

  • During the intense battles against Lord Tensen, Doshi, and other enemies, Gabimaru pushes his Tao far beyond safe limits, draining it almost completely.
  • Tao in this series is tied directly to a person’s body and mind, so overexerting it can warp both physical and mental states, including consciousness and memory.

How the memory loss shows up

  • After the big fight (anime episode 12–13 area), Gabimaru collapses and later wakes up in a cave, confused about how he got there and with foggy recollection of recent events.
  • When Mei views him with her Tao vision, she sees his Tao as if the upper half of his head is “sheared away,” symbolizing that his moral sense and memories have been badly damaged.

What parts he forgets

  • Gabimaru remembers that he is a deadly shinobi from Iwagakure and that he is on a mission for the Elixir of Life, so his old “Hollow” assassin persona resurfaces.
  • The memories that tethered him to his humanity—especially his wife Yui and his emotional connections to allies—are the ones that become blurry or inaccessible, making him colder and more ruthless again.

In‑story explanation of why Tao causes amnesia

  • The series establishes that Tao can change a user’s mental and physical state, from markings on the skin to behavioral shifts, unconsciousness, and in extreme cases memory loss or even death.
  • Characters explain that using too much Tao too quickly is especially dangerous; Gabimaru’s inexperience with Tao control makes the backlash worse, culminating in his amnesia instead of outright death.

Do his memories come back?

  • In the manga, Gabimaru does eventually regain his memories once his Tao is stabilized and balanced, particularly with Sagiri’s help, who discovers she can influence and restore Tao.
  • This recovery restores not just information but also the emotional weight of his bonds, pulling him back from the fully “Hollow” mindset.

Information gathered from public forums or data available on the internet and portrayed here.