Tear Jerker / Ninja Slayer

• Yamoto's goodbye to her best friend Asari in Episode 4, with a strong implication that they'll never see each other again now that she's forced to live life on the run as a ninja.
• The second half of Episode 7 features Ninja Slayer meeting a kindly old gentleman named Tomihide Sugawarano, whose estranged son closely mirrors his own background as Kenji Fujikido. Mr. Sugawarano shares a simple, but profound tale of life's regret that seems to resonate all too well with the tormented vigilante, and they part ways on a warm, friendly note. The ONA doesn't explore anything beyond that, but anyone who is familiar with the light novels' "Deadmoon on the Redsky" arc will know that Mr. Sugawarano's story does not end well.
• Episode 11, full stop. Having inadvertently led Darkninja into his ailing mentor's location, the outmatched Fujikido can only watch in horror as Dragon Gendoso, Japan's last surviving 'true' ninja, sacrifices his life in battle. With Yukano missing, his efforts at finding a cure gone all for naught, and the bad guys mere seconds away from unleashing an airstrike... a distraught Slayer is left with no other choice but to run, powerless to stop the Syndicate from torching whatever remains of the old shinobi's home to the ground.
• Episode 14, during Yamoto's fight against her sensei, Silver Karasu. After dispatching Third Eye, Karasu announces himself as the third assassin contracted to kill Yamoto, challenging her into a death duel, preferring death by her sword rather than succumb to his disease. But as the fight wears on, it dawns upon both combatants that neither intends to kill the other, and Karasu concedes, allowing a crying Yamoto to push him onto the ground. Yamoto admits that she immediately recognized him as Kagi Tanaka and can't bring herself to slay him. Tanaka apologizes, stating he shouldn't have expected someone of her mindset to be capable of granting such request. Silver Karasu then recites his death haiku, finally expiring in front of his student.
• Sums up the events of Episode 18 in spades, taken from the perspectives of both Ninja Slayer and a college student named Naraki:
  • Naraki's side of the story involves him joining a protest group in hopes of winning the heart of a girl he likes, only to end up in the middle of a violent and murderous riot. Then he finds out said girl was just using him, further rubbing salt into the wound.
  • On Slayer's end, he spends most of the episode trying to convince Amnesia into leaving the Ikki Uchikowashi. She rebuffs him by declaring her loyalty to these terrorists, showing that she's no longer the person he once knew as Yukano. In the end, he lets her go, pondering on what to do the next time they meet. You can almost feel the combined weight of conscience & disappointment on Slayer's shoulders as his segment draws to a close...
• Episode 20 ends on a bittersweet note. Ninja Slayer survives his fight against Khan and Darkninja, but fails to save his one last remaining friend & ally, Nancy Lee, with the grim knowledge that she'll be put to torture by Khan. Defeated and left severely wounded, his only ray of hope comes in the form of Maria, the woman he helped earlier, who finds him and tends to his injuries.