Voice actor Kōhei Amasaki wrote "Kirill is an idiot" on every script page to help stay in character.

DOUBLE DECKER! DOUG & KIRILL held a special talk show on October 27 for Bandai Spirits's Tamashii Nation 2018 event. Director Joji Furuta, character designer Masakazu Katsura, producer Kazuhiko Tamura, and voice actors Kōhei Amasaki (Kirill Vrubel) and Satoshi Mikami (Douglas "Doug" Bilingam) came on stage at the Akihabara UDX building to talk about the characters of DOUBLE DECKER! DOUG & KIRILL and how they were conceived.

DOUBLE DECKER! DOUG & KIRILL is an original anime production, meaning that all of the characters were designed from scratch. Furuta said that he likes police dramas, detective stories, and steampunk, so he based the story and characters around those elements. The anime made it to television after three years of production.

Katsura noted that he didn't know much about the characters' personalities or histories when he was initially asked to draw them. For instance, the only thing he was told about Kirill was that he's androgynous. He didn't even know that Kirill's defining personality trait is that he is “a big idiot.”

For Doug, he was told to draw a good-looking man with curly hair. He had trouble imagining what Doug was like at first, but got a better idea of the character after his personality was explained to him.

When asked which character he liked drawing best, Katsura responded that he liked all of them equally this time. When asked specifically about the character of Maxine "Max" Silverstone, Katsura said that he liked drawing her because she has the kind of hairstyle that you don't often see in manga. He said that he only feels half the responsibility for creating these characters so he feels that he can draw whatever comes to mind.

Even the voice actors don't know everything there is to know about the DOUBLE DECKER! DOUG & KIRILL characters. Furuta has not been giving away spoilers and notes that it's hard to convey through the script what a stoic character like Doug is supposed to be thinking. Mikami said that he's looking forward to finding out Doug's secrets. He finds that he understands Doug's character better through doing the recording and being surrounded by the other characters. “I can't help but make my voice sound gentler when I'm actually doing the recording,” he said.

As for Amasaki, he said that he tries to keep all the things he knows about a character in mind when he acts. For that reason, he wrote “Kirill is an idiot” on every page of the script, just so that he wouldn't forget. Furuta said that Kirill's idiocy comes through strongly in the script because the series composition writer Tomohiro Suzuki kept adding in those parts, saying, “Kirill is cute when he's being dumb.”

Later in the show, the upcoming figures of Doug and Kirill were previewed for the audience. All who were present agreed that figures were of very high quality and that they captured the expressions and other details of the characters very precisely.

It was interesting watching the staff and cast members talk about DOUBLE DECKER! DOUG & KIRILL as excitedly as any other fan. In closing, Mikami and Amasaki said that they enjoyed the “buddy cop” feel of the anime and hope that their voice acting can do justice to its characters.

Crunchyroll is streaming DOUBLE DECKER! DOUG & KIRILL worldwide except for Asia.