"Hortensia Saga: Blue Knights") was a Japanese free-to-play role-playing video game developed and published by f4Samurai and Sega.

[12] The series was directed by Yasuto Nishikata and written by Rintarō Ikeda, with character designs by Takayuki Onoda and music by Zenta.

[14] Mafumafu performed the first ending theme "Night Dream and Daydream" (夜想と白昼夢, Yasō to Hakuchūmu) from Episodes 1–7 and 9–12, while Yui Horie performed the second ending theme "VEIL" for Episode 8 as her character Mariel D'Hortensia.

[14][15] Funimation licensed the series and streamed it on its website in North America and the British Isles, in Europe through Wakanim, and in Australia and New Zealand through AnimeLab.

[16] On October 29, 2021, Funimation announced the series would receive an English dub, which premiered the following day.