‘The Door Into Summer’ Ending, Explained – How Soichiro Reclaimed His Invention?


Based on the novel of the same name by Robert A. Heinlein, “The Door Into Summer” is a story set in 1995 Japan. It follows Soichiro Takakura, a young engineer in his late 20s passionate about robotics. He has his own company and has created a revolutionary robot. But it all fades away when he is betrayed by his girlfriend. Devastated by the loss, Soichiro descends into a cryosleep for 30 years.

‘The Door Into Summer’ Plot Summary

Soichiro Takamura loses his parents at an early age and his father’s friend, Professor Matsushita, takes him into his family. The Professor’s daughter, Riko, also grows fond of him. Soichiro learns a lot from the Professor and also gets his liking for robotics from him. A few years later, when Soichiro is already a grown-up and doing his own research, the Professor passes away. Riko is still studying in school, so she starts living with her uncle while Soichiro lives with his long-time companion, Pete, his pet cat.

Soichiro has developed robot A-1, but he wants to develop it further by adding a regenerative plasma battery to it, which was Professor Matsushita’s idea. Soichiro’s girlfriend, Rin, has been supportive of his research but is jealous of Riko because of her closeness to Soichiro. When Soichiro is transferring some of his shares from his company to Rin, she asks him if he is keeping her close to make Riko feel better. Riko has feelings for Soichiro, and even if they don’t live together, she knows everything in Soichiro’s house. Does Soichiro really like Rin, or is he keeping her by his side for the sake of Riko, like Rin believes?

Major Spoilers Ahead

Why Does Soichiro Go Into ‘Cold Sleep’?

Kazuhito is the late Professor’s brother and partner in Soichiro’s company FWE. Kazuhito calls Soichiro for an urgent shareholders’ meeting. He wants to launch the robot A-1 into the market because of the buzz it is making and competitors trying to copy it. Soichiro opposes the idea because he still needs to develop it further to accommodate the plasma batteries. As a new shareholder, Rin is also part of the meeting, and she asks them to take a vote. She nods at Soichiro, indicating that she will support him, but when her turn comes, she votes against him.

Soichiro loses the right to his own invention. He becomes a mere shareholder in the company. He cannot develop his robot further as Kazuhito cuts off all his funding. Rin was only acting as Soichiro’s girlfriend, and it was her and Kazuhito’s plan all along to cheat Soichiro. Without his research, invention, and robot, Soichiro’s life is left with no meaning. He registers for a cold sleep program because his present life is too difficult for him to handle, and he wants to wake up to a different future. Though he has already registered, he thinks of his cat, Pete, who opens every door in the house whenever it snows. Pete does not like winter and feels that by opening the door, summer will come. Although Pete fails most of the time, he never gives up. The stance explains the title as well as the theme of the narrative.

Soichiro Takakura's cat, Pete
Credits: Netflix

He decides to fight back and goes to Kazuhito’s house. Riko hears the conversation between her uncle and Rin and runs away to meet Soichiro. Meanwhile, Soichiro is at Kazuhito’s house with Rin alone. He threatens her to expose their fraud to the media. Rin distracts him and injects him with Kazuhito’s insulin. While Soichiro lies unconscious, Rin finds out about his cold sleep registration. This works in her favor, and she puts him to sleep, but in another company’s program. At The Mannix, where she used to work, before he sleeps, she tells him the secret of tax fraud. Fate doesn’t work in Soichiro’s favor, and he goes to sleep for the next 30 years.

How Does Soichiro Time-travel?

Soichiro wakes up 30 years later, in 2025, to find out that the company Mannix, which was responsible for his cryosleep, has gone bankrupt, and all of his assets have been lost. After waking up, he is supposed to rest in the hospital for five days, and the humanoid robot PETE-13, who is Soichiro’s nurse, looks after him. Soichiro wants to go, but Pete won’t let him go. Soichiro uses his wit to trick the robot and runs away, but Pete follows him. When Soichiro commands Pete to go back to his work, Pete says that he has finally escaped and that he is called a malfunctioning robot for being over-curious about humans.

The doctor has given him an address which is supposed to be Riko’s, but Soichiro finds Rin instead. Her life has gone downhill since the financial fraud of Mannix came to light, as she had helped them. After Kazuhito died, FWE was taken over by another company called Guardian, and now it is known as FWEG. However, Soichiro’s Plasma Battery rights are not with them but with another company called Aladin. Soichiro meets the new president of FWE, gets the list of FWE’s old shareholders, and finds an unknown name, Sato Taro, on it. He wonders how this man got the shares and who he exactly is. The man is the owner of the company Aladdin, but he has credited Soichiro as the inventor of their robots. His questions are answered when the president of FWEG, Tsuboi, tells him they met each other when he was a kid.

Although Soichiro does not remember anything, Tsuboi tells him how Soichiro and Professor Toi met in his father’s restaurant. Professor Toi was inventing the time-travel machine at the time. This hints Soichiro into thinking his future self must have traveled back to help him. He finds Professor Toi, and the Professor confirms that it is indeed true. The Professor has completed the time machine with the help of money that Soichiro had given him in the past. He prepares to send him back in time. When Soichiro cannot handle the power of the Machine, Pete jumps in with Soichiro, and now, they are both back in 1995.

Soichiro Takakura's robot
Credits: Netflix

‘The Door Into Summer’ Ending, Explained

Soichiro already knows the series of incidents that are going to happen. To do damage control, he takes the matter into his own hands. He travels back 8 days before he went into cold sleep in 1995. They meet the lawyer, Sato Taro, and follow Pete’s orders. They make an entire plan to save Soichiro’s invention from falling into the wrong hands. Soichiro starts completing the blueprint for the robot. Soichiro Sato is helping him just as a lawyer, but Soichiro has a different plan for him. Soichiro Sato will become president of the company “Aladdin” with Soichiro’s invention.

Soichiro is running behind schedule on the D-day, but Pete reassures him and hijacks the truck with all Soichiro’s documents. By this time, Soichiro has finished his blueprint, and he goes and gets Riko, who is waiting for him at his house. While on their way to Sato’s house, Soichiro explains everything to Riko. Riko will live her life as an adopted daughter of Sato further on.

Pete stays with Riko, and Soichiro departs to a cold sleep again. He goes into the program that he had initially registered for. The present-day Soichiro is going to be put to sleep by Rin. While Soichiro is sleeping, Riko grows up to become a robotics scientist herself and goes into cold sleep for 20 years to wake up together with Soichiro. Soichiro wakes up again after 30 years to find Pete waiting for him, and Riko will wake up from her cold sleep after 20 years. His final robot blueprint is adapted to make the humanoid robots, and he is credited as a developer. His inventions are finally his own. 

In Conclusion

Among all the drama, the sci-fi part of The Door Into Summer is disappointing. The focus on the emotional life of Soichiro made the scientific part weaker. If both the present and future Soichiro are in cryosleep simultaneously, aren’t they both waking up in the same world at the same time? This could create a loop in time and space, but there is no mention of it. Instead, Riko and Soichiro get together after 30 years. This is indeed the highlight of the movie. If you’re hoping for good sci-fi, the only worthwhile things are cryosleep and humanoid robots. For the rest of the film, one can expect a good melodrama.

The Door Into Summer is a 2021 Science Fiction Drama film directed by Takahiro Miki. It is based on a novel written by Robert A. Heinlein.

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Neha Bhondve
Neha Bhondve
Neha is an Entertainment Writer and a Korean language and culture enthusiast. She loves to explore new people and places and when not writing, she is either learning Korean, reading a book or making a new travel plan.

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