OttoKallen

OttoKallen is the het ship between Kallen and Otto from the Honkai fandom.

Quotes
"Otto… Do you still dream of making a flying machine?"

- Kallen

"To save the one and only her, I can only create new possibilities in the past. The other future will belong to her…"

- Otto

Trivia

 * In the official description of “Elan Palatinus” is "Year of our Lord 1470, Schicksal rallied the princes of Europe and unleashed a Crusade to conquer the Far East, only to be defeated by an immortal warrior. Kallen Kaslana, a powerful Valkyrie warrior, must make a choice between love and her oath". Since Yae Sakura was not mentioned in the manga, the sentence "to make a choice between love and duty" is about Otto.
 * In the box with the letter to Otto, Kallen Kaslana left two roses, which according to Chinese traditions are considered a sign of apology between lovers.
 * In “Thus Spoke Apocalypse” before little Otto and Kallen were shown sleeping by the tree, there were two bright stars, Altair and Vega. Old Chinese legend tells of the forbidden love story between the goddess Zhinü (symbolized by the star Vega) and the cowherd Niulang (symbolized by the star Altair).