Development Hell: In the collected volume for the manga's finale in 2004, author Kentaro Yabuki expressed intentions to create a sequel series. However, his work as artist on To Love Ru (and it's sequel Darkness) proved so successful, he instead went with his other stated option of continuing Train and Eve's story via their Expies Kuro and Yami.
Pop-Culture Urban Legends: Though Shiki is androgynous and uses gender-neutral language, he is officially male in every version of the manga and anime, which is essentially uncontested in the Japanese fandom. The manga's English fan translators assumed Shiki was a girl once he was unmasked, creating a myth in the series' English fandom that both the anime and official English translations changed Shiki from female to male.
