>>280710846
Ootsuka worked on the two OPs and 5 episodes, including the first episode and season 1 finale.
Yoshioka is freelance and has worked with the director before. Really she didn't just do background art on Frieren (though she did do background art on Tenki no Ko, 5 Centimeters Per Second, and other stuf), she also did concept art and world building (setting layout).
https://www.animenewsnetwork.com/encyclopedia/anime.php?id=26334
Here's an interview worth reading. She made maps of everything and made the concept art for various cultures, iconography, flora, and so on for various regions/environments.
https://www.reddit.com/r/Frieren/comments/1dt213x/mdn_interview_with_frieren_lead_concept_artist/
> ──You were in charge of concept art for the anime "Furiren: The Funeral of Frieren," which began airing in September 2023. What role does concept art play in anime?
>Yoshioka:　Concept art is created in the early stages of pre-production to illustrate the overall atmosphere and direction of the work so that everyone on the staff can have a common understanding.
>The art director is also involved in creating a worldview, but perhaps I should say that I am one step ahead of the process. In "Furieren: The Funeral of Frieren," I drew the "setting layout" that would become the master shot of the location, and then the art director, Sawako Takagi, drew the "art board."
I just chose a random twitter post by the way. You should browse her twitter, she has a lot of behind the scenes art on there.
https://x.com/seiko11/status/1720456774744945094
>>280710710
I can't even think of any other anime originals by Madhouse other than Sora Yori