- And the Fandom Rejoiced: The news that an anime adaptation was in the works caused mass celebration throughout the fandom.
- Foe Yay - Akari and Hirato's relationship, though mostly one-sided and amusing when they're not being serious.
- Ho Yay - As with many manga serialized in ZeroSum, Karneval has ample hints of Ho Yay, from Gareki's looking after Nai all the time (Nai's innocence particularly affects him), to Yogi's perceived friendship with Gareki (thinking of him as cute because of the deredere side of Gareki's Tsundere characteristics), to Hirato and Akari's Foe Yay, to Yogi's attempts to gain Hirato's praise...
- Much like Hinoe from Natsume Yuujinchou, Eva dislikes men and prefers the cute softness of girls, like Tsukumo.
- Iron Woobie: Gareki. The guy really did have a terrible childhood.
- Tear Jerker - After Yotaka is killed in front of her eyes, Tsubame breaks down and loses the will to live, begging Yogi to kill her too as she cannot stand to be alone. She then offers herself to Circus as a test subject, knowing she will have to undergo horrific experiments and a great deal of pain. She then visits her dying grandfather to say goodbye, and realizes that Gareki was stealing to pay for his medicine all this time... BUWAAAAAAAAH!