An original anime by Studio Elle and l-a-unch・BOX that premiered on July 8 for the 2020 Summer season. The story is as follows: The year is 2030, and Japan has… a huge problem to say the least. People are turning into monsters thanks to a mysterious disease known as Gibia. But hope still isn’t lost, as a samurai named Sensui Kanzaki, and a ninja named Kenroku Sanada from the Edo time period have traveled forwards in time to this Bad Future. Meanwhile, a scientist named Dr. Yoshinaga is trying to create a cure for Gibia, with his assistant Kathleen joining Sensui and Kenroku to try and put and end to this.
General Tropes:
- 2D Visuals, 3D Effects: The Giba and various vehicles are often depicted through 3D animation.
- 20 Minutes into the Future: The story is set in 2030, with the pandemic beginning in 2028 as mentioned by Kathleen.
- Action Girl: Ayame not only is very good with her tonfas, she's also very good with a shotgun.
- Animalistic Abomination: The Gibia come in all shapes and sizes, some looking like mammals, insects, and even dinosaurs.
- Audience Surrogate: Sensui and Kenroku are as in the dark about the Gibia as the audience, so when Dr. Yoshinaga explains it to them, the audience learns too.
- Bald Mystic: Yukinojo Onikura is a Warrior Monk, and as such he's bald other than a goatee and some braids.
- Bare Midriffs Are Feminine: The outfit Kathleen wears exposes her navel. The same with Ayame's outfit and they're the two most prominent female characters, while males wear modest clothing.
- Break Out the Museum Piece: The party encounters an exhibition of samurai weapons, and Sensui finds his old swords, while Kenroku finds his armed gauntlets and Yukinojo finds the club from one of his old comrades.
- But Not Too Foreign: Kathleen's name and blonde hair indicate she's biracial, with a picture of her father showing he was blonde too.
- Combat Pragmatist: As expected from a ninja, Kenroku uses any weapon at his disposal, like wires and hand grenades.
- Cool vs. Awesome: A samurai and a ninja from the Edo Period against human turned-monsters from the Modern Age. The former are later joined by a Sengoku period warrior monk.
- Cultured Warrior: Sensui is also a skilled at playing the shimasen, and he plays it after a major battle.
- Disappeared Dad: Kathleen's father died when she was four years old.
- Dislikes the New Guy: Many of the survivors at the camp distrust both Sensui and Kenroku after they arrive, with the exception of Kathleen's mother, Brian and Yoshinaga.
- Downer Ending: The series ends with Kathleen and Kenroku leaving Japan on a boat to places unknown and Sensui deciding to stay behind after being stung by Gibia to fight off a horde.
- Dual Wielding: Sensui fights with his katana Setsuomaru and a western sword.
- Fish out of Temporal Water: Sensui and Kenroku were being transported to from the Edo Period to the year 2030, so many things are alien to them. They are later joined by Yukinojo the monk, who comes from the Sengoku period.
- Gentle Giant: Yukinojo is huge and incredibly strong, yet he's a pretty cool guy who blushes when complimented by Kathleen's mother.
- Heroic Sacrifice: Adam the marine, finding himself infected, takes a grenade and blows up himself and as many Gibia as possible in order to allow the group to escape.
- Identical Stranger: According to Kenroku, Kathleen bears a great resemblance to his lover Okuni except with black hair.
- Insectoid Aliens: What the Gibia actually are, and anybody unfortunate enough to be stung by one becomes one too.
- The Mentally Ill: While Kathleen's mother Yurika can act normal and professional most of the time, trauma has made her incapable of differentiating humans from Gibia.
- Mr. Exposition: Kathleen and Yoshinaga on the first episode. Kathleen explains the setting and how it spread on a video log, while Yoshinaga explains our time-shifted ninja and samurai what are the Gibia and how the infection and transformation occurs.
- Ninja: Kenroku mentions he's a shinobi, and seems capable of reacting so fast it looks as if he teleported.
- One-Man Army: As soon as Sensui gets into battle, Gibia are sliced up by the dozens.
- Ramming Always Works: Kenroku manages to kill a large Gibia by ramming it and crushing it while piloting a helicopter.
- Razor Wire: Kenroku manages to kill a Gibia by binding it with some wires. It's still exhausting for him trying to hang a monster the size of a horse.
- Red Baron: Sensui used to be known as the Slayer of a Thousand, and he certainly lives up to the title.
- Red Eyes, Take Warning: Whenever Sensui is feeling particularly bloodthirsty, his eyes glow red.
- Sacrificial Lamb: Maeda, the nice old man who was a grandfatherly figure for Kathleen, dies during episode 2 after giving to Sensui his beloved katana.
- Take Up My Sword: Maeda, the old man who loves samurai, gives his katana to Sensui after being fatally injured by a Gibia.
- Tall, Dark, and Handsome: Sensui, who is taller than Kenroku and not bad looking at all.
- The Virus: The Gibiate infection, which turns people into various types of monsters who in turn are driven to infect other humans.
- Was Once a Man: Infected people turn into monstrous Gibia if they become stung. Apparently those infected start hearing water and after five hours the metamorphosis occurs.
- Yakuza: Ayame's father is one, which is a very sore point for her; she even became a cop specifically to arrest him.
