Her father protects her staying by her side as she starts gradually turning into a young child due to loss of memory and a loving accompaniment begins.

[5] In June, 2021 the cast of the film, tentatively titled as Dementia was confirmed as Ahn Sung-ki and Seo Hyun-jin.

[13] As of July 14, 2022[update] it is at the 29th place among all the Korean films released in the year 2022 in South Korea, with gross of US$148,789 and 22,149 admissions.

Concluding, Lee revealed that for Cassiopeia director Shin Yeon-sik got the idea from the similar relationship between Robert De Niro and Anne Hathaway in The Intern so for the director due to his relationship with Ahn Sung-ki, "Cassiopeia had to be the story of a woman who has her father as Ahn Sung-ki.

"[15] Park Jin-young reviewing for Joy News 24 wrote about the film, "The movie captures the situation of Alzheimer's patients and their families, as well as their companionship, with a calm gaze without exaggeration or belief."

Park praised the performances of Seo Hyun-jin, writing, "Seo Hyun-jin's passionate performance, which solidly depicts various roles and swirling emotions, from lawyers to maternal love to Alzheimer's, draws admiration," and Ahn Sung-ki, writing, "Ahn Sung-ki leads the play stably with a heavy presence and deep eyes.