I want to wear a ring

Teruhiko Katayama (played by Takayuki Yamada), male, 29 years old, ace salesman of Akafushi Pharmaceutical Company. One day he accidentally fainted. When he woke up, he suffered temporary amnesia due to a blow to his head. There was a ring hidden in his bag, but he had no clue who he was going to give it to. At the same time, three women with completely different backgrounds and personalities alternately appear next to Katayama, namely the beautiful and talented Sumitomo Chie (played by Konishi Manami), a senior in the same company, the cheerful and optimistic busty girl Shiozaki (played by Yoko Maki) in the custom shop, and Suzuki Wakako (played by Chizuru Ikewaki) who is often scarred when performing puppet shows in the park. It seems that Katayama has been dating them at the same time. As the battle for the ring escalates, Katayama is gradually brought back to the origin before amnesia... This film is adapted from the novel of the same name by the Akutagawa Award-winning writer Ito Mizuki.