Season 1

Young Shinoha Tanaka, who has lost the ability to laugh, meets Kiwami Kimura, an office worker who shares his love of anime. The two hit it off, but it turns out they are actually members of rival forces that have been killing each other since the Edo period - ninja and gokudo! "If you misbehave in the underworld, the ninja come a-calling." Ninja and gokudo - who will survive and who will perish?

Kaiza Akiba of the Eight Imperial Ninja's arrival cuts the gokudo's meeting to plan the ninja's annihilation short. Kaiza's Blade of Darkness instantly decapitates numerous gokudo, bathing the room in crimson. However, Kiwami maintains his calm demeanor, which riles up the remaining gokudo. As these two formidable warriors go in for the kill, their thoughts are somewhere else... with Shinoha.

Nodoka Matsumoto of the Eight Imperial Ninja and Kousei Yuzawa of the Eight Gokudo of Destruction are locked in a deadly battle in Kabuchika, once an underground Kabukicho club. Who will survive the clash?! Rushing to aid Nodoka, Shinoha encounters young gokudo member Keisuke. Keisuke has never killed before, and Shinoha intends to spare him, but Keisuke's resolve forces Shinoha to act.

Both burning with hatred in the aftermath of Kabuchika, Shinoha and Kiwami take a spontaneous nighttime drive. They learn of each others' loss while discussing Flash Princess and make an inspiring pledge to each other... Charismatic figures from each side, the Cursed Blood Ninja Brothers and the gokudo's bosozoku "god," each rally their troops. There's no running from this deadly battle of fate!

I'll make our dream come true! Wishing to bring back their "golden age," bosozoku "god" Hiroki Yajima raises a 30,000-strong biker gang that barrels down the Teito Highway, drenching it in blood and flames! But Zanzo and his ninja are up for the fight and lie in wait at five points along the highway to confront the rampaging Seikaten Biker Gang Army.

Yajima toys with Shinoha and pierces his skull with Pistol Disco. Shinoha gambles with his life... but survives by the skin of his teeth! At first, the ninja's strength impresses Yajima, but he soon becomes irritated when Shinoha points out that his regrets are why he has to rampage. Cornered by Shinoha's monstrous power, memories of his beloved daughter flash through his mind.

Shinoha and Kiwami mourn their fallen comrades, while Gamute sticks close to his Mommy. Rage and a thirst for blood burns in them all. Thanks to Shiki, Shinoha learns the secret of Gamute's special ability, and his resolve hardens. Amidst this, Shinoha runs into none other than Prime Minister Kanshichi Aida, who is visiting the Princess Store incognito. The story takes a further turn.

Shinoha attends the award ceremony at the Prime Minister's residence. Kiwami is there to celebrate this honor with his friend... but the festivities turn into a nightmare when the Glass Children suddenly storm the building. Gamute declares the beginning of a deadly game involving the civilians and the wheels of fate begin to turn for Shinoha and Kiwami!