The Door Into Summer is a 2021 Japanese film directed by Takahiro Miki, based on Robert A. Heinlein's 1956 novel of the same name.
Soichiro Takahura has had a life filled with tragedy. His mother died soon after he was born, followed by his father when he was seventeen. He was then taken in by his father's colleague, robotics expert Dr. Koichi Matsushita, only for him and his wife to die in a plane crash a few year later. Soichiro is left almost completely alone in the world, except for his pet cat Pete, and Dr. Matsushita's young daughter Riko, who goes to live with her uncle Kazuhito.
The story opens in 1995, where Soichiro has followed in the footsteps of his father and Dr. Matsushita to become a talented robotics engineer, as well as a major shareholder in the robotics company founded by his mentor and managed by Kazuhito. He remains oblivious to the affections of the now-teenage Riko, in favor of his gorgeous fiance and company secretary Rin Shiraishi.
Rin convinces Soichiro to sign over a significant share of the company, only to later conspire with her lover Kazuhito to seize control of the company and sell it to the conglomerate Mannix Corporation, kicking Soichiro out from his own company, depriving him of his research materials and robot prototype, leaving him with a handful of non-controlling shares.
Opting to enter cryogenic sleep to escape his troubles, Soichiro awakens thirty years later in 2025 to an advanced society served by humanlike service robots, and with no assets to his name. While searching for Riko's whereabouts, he instead encounters Rin, now a bitter drunk after Kazuhito died, Mannix folded and she herself was imprisoned for tax evasion, all while the shares intended for her were taken by...someone.
Assisted by an ultra-sophisticated android also named Pete (PETE-13), Soichiro sets out to solve the mystery.
Tropes:
- Adaptation Distillation: A few subplots from the novel are abridged to fit the runtime of the film:
- Daniel's months-long adjustment to life and engineering technology in 2000 are dropped in favor of Soichiro spending a few days in 2025 to investigate the fate of Riko and the FWE shares intended for her.
- Daniel spent some time convincing the Suttons to help him after returning to 1970; when Soichiro awakens from his time jump back to 1995, Sato tells him that PETE-13 had already explained everything to him, the gold has been cashed out and the rest of their plan is underway.
- Similarly, Daniel has to track down and butter up Dr. Twitchell in order to eventually goad the latter to send the former back in time, whereas when Soichiro first meets Professor Toi in 2025, the good doctor eagerly ushers the inventor to his time machine.
- Adaptation Name Change:
- Soichiro Takakura = Daniel Boone Davis
- Riko Matsushita = Frederica "Ricky" Virgnia Gentry/Heinicke
- Kazuhito Matsushita = Miles Gentry
- Shiraishi Rin = Belle S. Darkin
- Taro and Midori Sato = John and Jenny Sutton
- Gota Tsuboi = Chuck Freudenberg
- Professor Junnosuke Toi = Dr. Hubert Twitchell
- Future Works Enterprise (FWE) = Hired Girl, Inc.
- Guardian Manufacturing = Geary Manufacturing
- Adaptational Nice Guy: The novel's Dr. Twitchell is a bitter drunk who needs to be goaded into sending Daniel back in time, whereas the film's Professor Toi immediately and enthusiastically helps Soichiro. Justified in that Soichiro is destined to return to 1995 and provide Toi's disgraced past self with the funding needed to eventually complete the time machine, as well as inventing the Plasma Battery to power it.
- Adaptational Skill: While Ricky of the original novel served solely as Daniel's Love Interest and rival to Belle for his affections, a young Riko shares an interest in robotics and electronics with Soichiro, foreshadowing her eventual role as the inventor of the second-generation PETE-2 robot.
- Age Lift: Heinlein's novel featured a romantic subplot between the 30-year-old engineer Daniel and the 12-year-old "Ricky" (Frederica), with Ricky following Daniel into cryo-sleep at the age of 21 so that she could later marry him at more socially-appropriate ages. The film reduces the squickiness by making Soichiro 27 and Riko 17, reducing their initial age difference.
- Alternate History: A low-key version, presenting a 1995 where teleportation and cryogenic sleep are possible.
- Anguished Declaration of Love: A crying Riko confesses her long-held feelings to a despondent Soichiro. However, he rejects her due to their significant age difference and the reeling aftermath of Rin's betrayal, opting to go into cold-sleep instead.
- Applied Phlebotinum: Soichiro's Plasma Battery, a semi-perpetual energy source that would revolutionize the service robot industry by making it possible to power androids such as PETE-13, as well as Professor Toi's time machine.
- Ascended Fanboy: A young Gota Tsuboi in 1995 is inspired by a news broadcast celebrating Soichiro's development of the A-1 robot prototype (along with a time-travelling Soichiro autographing his science textbook) to eventually become the President of Guardian Manufacturing, a key player in the service android industry in 2025.
- Bland-Name Product: PETE-13 shows Soichiro a video about the disgraced Professor Toi on Wootube.
- Bonding Through Shared Earbuds:
- Riko and Soichiro's closeness is demonstrated when she takes one of the earbuds Soichiro is listening to and plugs it into her own ear.
- Later PETE-13 does this, showing how he and Soichiro are becoming friends.
- Career-Ending Injury: Sato's wife Midori was once a tri-athelete, until a traffic accident confined her to a wheelchair.
- Compartment Shot: Combined with P.O.V. Cam. A compartment shot shows Rin opening Soichiro's bag, only be to be clawed in the face by Pete the cat, who was hiding inside.
- Compound-Interest Time Travel Gambit: Goes wrong for Soichiro when he's awoken from cold sleep only to learn that Mannix went bankrupt and he has nothing.
- Dramatic Drop: PETE-13, who is supposed to stay behind in 2025, dramatically drops the music player he's holding, and jumps up onto the time travel platform with Soichiro, resulting in both going back to 1995 together.
- Drowning My Sorrows: Soichiro gets heavily drunk after finding out that his fiancee Rin was actually Kazuhito's lover and conspired to wrest control of FWE from him. This causes Credeus to postpone his original cold sleep appointment, although Rin arranges for a Mannix subsidiary to freeze him anyway.
- Earn Your Happy Ending: Soichiro's actions throughout the film ultimately ensure that history rightfully credits him as a pioneer in robotics and the inventor of the Plasma Battery, while reuniting him with his beloved Riko and Pete the cat. Furthermore, he inspires Gota Tsuboi and Taro Sato to become the heads of market leaders in the robotics industry, helps Professor Toi vindicate his time travel theories, and fulfills a crippled Midori Sato's wish to have a daughter (Riko via adoption).
- Evil-Detecting Dog: Pete the cat hisses at Rin, who we later find out is scheming to cheat Soichiro out of his company.
- Foreshadowing:
- A news segment seen during the opening scenes depicts Professor Toi of Teito University publicly and successfully demonstrating reliable teleportation. The miniature teleportation device heavily resembles the time machine that Soichiro will use later in the movie.
- A TV commercial also in the opening scenes advertises "cold sleep", the opportunity to go into cryonic freeze and wake up years or decades into the future. This is what happens to Soichiro later in the movie.
- Kazuhito is seen giving himself an insulin injection, because he has diabetes. Later Rin gets the advantage of Soichiro by jabbing him in the neck with one of Kazuhito's insulin syringes.
- Grew Beyond Their Programming: PETE-13 is initially assigned as a nurse to help Soichiro transition to the advanced society of 2025; he eventually learns to selectively disobey orders, learns human empathy and assists Soichiro on his own accord.
- Happily Adopted:
- Soichiro by the Matsushitas, at least until the plane crash that killed both adoptive parents.
- Riko (eventually) by the Satos, keeping her safe from the machinations of her uncle Kazuhito and lover Rin.
- Human Popsicle: Soichiro actually decides to not do this, only to get drugged and put in cold sleep by Rin. Later he voluntarily does it to go back to 2025, only to find that Riko spent 20 years in cold sleep to join him.
- Identical Grandson: Soichiro wakes up in 2025 and is startled by the sight of the same cold sleep technician he first met thirty years ago in 1995. The technician explains that actually, that was his father.
- Impairment Shot: A shot from Soichiro's POV as his vision blurs, after Rin jabs him in the neck with one of Kazuhito's insulin shots.
- I Was Quite a Looker: 1995 Rin is a petite, attractive company secretary, while 2025 Rin is a overweight, pill-popping and drunk pensioner.
- Lady Drunk: Soichiro finds Rin in 2025, living in a filthy apartment, with empty beer cans scattered around, popping pills, and very, very fat. Rin angrily shouts at him that Kazuhito died and Mannix folded and she went to jail for cooking Mannix's books.
- Line-of-Sight Name: Sato names his future company Aladdin Industries after a poster of Aladdin's lamp on the wall of the room Soichiro is temporarily staying in.
- Made of Iron: PETE-13 easily survives a collision with the FWE truck carrying Soichiro's research materials with not so much as a scratch, and proceeds to hijack it.
- Maybe Ever After: In contrast to the original novel where Daniel unambiguously takes an older Ricky as his wife after both arranged for her to enter cold sleep when she turns 21, Soichiro only learns from Sato's letter that Riko entered cold sleep out of her own accord to be with him, and along with his lingering regret from having to part with her again in 1995, finally has a Love Epiphany. When Riko later wakes up in the recovery ward of the cold sleep clinic, Soichiro is by her bedside holding her hand.
- Never Found the Body: Despite Rin in 2025 insinuating that Riko was killed in the explosion that destroyed the Matsushita family home and Soichiro's private workshop, her body was never actually found. After returning to 1995, Soichiro arranges for the Satos to adopt Riko, ensuring her safety while fulfilling the Stable Time Loop where he earlier stumbled across Riko's gravestone in a cemetery.
- Not What It Looks Like: A man at a urinal in a public restroom hears someone in a stall saying "Take your shirt off!", and someone else saying "As you wish." It's Soichiro telling PETE-13 to show him PETE-13's Plasma Battery, which is what makes advanced robots like PETE-13 possible.
- Oblivious to Love: Soichiro has no idea that Riko is in love with him. Their ten-year age gap, being raised together as step-siblings, and the presence of his smoking hot fiancee Rin may be contributing reasons.
- Pragmatic Adaptation: One of the original novel's plot threads of a 30-year-old man gradually falling in love with a 12-year-old girl proved to be highly controversial, despite being first published in a time where significant age differences between romantic partners were more tolerated; in particular, Daniel and Ricky had joked about getting married since the latter was six, and towards the end Daniel tells Ricky to enter cold sleep herself and promises to marry her when she is older. The film softens the squickiness by reducing the age gap between Soichiro and Riko to ten years, raising Riko's age to 17, and portraying Soichiro as Oblivious to Love; even Riko's decision to enter cold sleep herself to reunite with Soichiro at a more appropriate age comes as a surprise to him in the end.
- Ridiculously Human Robots: The service androids that exist in 2025 are indistinguishable from humans, except for a certain Uncanny Valley manner, the times when they show off their digital irises, and (at least in PETE-13's case) a hidden holographic display on their forearm showing their manufacturing details (e.g. PETE-13 being a product of Aladdin Industries).
- Secret-Keeper: Unlike the Suttons of the original novel (who merely follow along with Daniel's plans with bemusement), the Satos are fully aware that Soichiro and PETE-13 are time travellers, and have all the information needed to actively assist them.
- Setting Update: The film is updated to 1995/2025 from Heinlein's 1970/2000, mostly to avoid some of the Zeerust that plagues the novel in latter days (among other things, Heinlein like many sci-fi authors didn't anticipate personal computing).
- Stable Time Loop: Several plot threads are affected by the same loop:
- While Soichiro originally booked his cryo-sleep with Credeus, Rin instead arranges for Soichiro to be frozen by a Mannix subsidiary. After implementing his plans in 1995, Soichiro makes it to his original appointment at Credeus to return to 2025.
- Soichiro meets PETE-13, an advanced android based on the PETE-1 robot and powered by the Plasma Battery he would eventually invent when he returns to 1995.
- Gota Tsuboi, the President of Guardian Manufacturing, claims Soichiro inspired him as a child to get into robotics. In 1995, Soichiro visits the Tsuboi family restaurant, where he autographs a young Gota's science textbook and offers him words of encouragement.
- While investigating how Guardian Manufacturing bought out FWE using shares intended for Riko, Soichiro learns that the shares were transferred to business tycoon Taro Sato, the founder of Aladdin Industries and an early shareholder in Guardian Manufacturing; furthermore, Sato is listed as Soichiro's patent attorney for the PETE-1 and the Plasma Battery patents. In 1995, Soichiro meets the lawyer Sato, who has been briefed by PETE-13 and provides Soichiro with room, board and resources to complete the design work for the two technologies; in exchange, Soichiro retrieves the FWE shares from his pickup truck and bestows them to Sato.
- Professor Toi claims that Soichiro's funding and Plasma Battery was what made his time machine a reality. In 1995, Soichiro (during the same visit to the Tsuboi family restaurant) offers a younger and disgraced Toi the money and encouragement needed to complete his research.
- An embittered and drunk Rin rants that she never received her FWE shares and was jailed for tax evasion, leading to the downfall of Mannix. Back in 1995, Soichiro asks Sato to probe into Rin Shiraishi and Mannix's finances.
- Riko Matsushita was presumed dead in the explosion that destroyed the Matsushita family home and Soichiro's private workshop, while in 2025 Soichiro learns that a Riko Sato had went on to develop the second-generation PETE-2, based on Soichiro's own PETE-1 patent. In 1995, Soichiro sets fire to his old workshop and arranges for the Satos to adopt Riko, keeping her safe from the scheming Kazuhito and Rin while ensuring she will eventually become a talented engineer in her own right.
- Kazuhito and Rin order Soichiro's research materials and A-1 prototype robot to be confiscated, but the FWE truck carrying them disappears afterwards. Upon returning to 1995, PETE-13 hijacks the truck and takes it to the Sato residence, with the recovered materials eventually becoming the seed intellectual property for Guardian Manufacturing.
- Pete the cat disappears during Soichiro's confrontation with Rin at Kazuhito's mansion. When Soichiro later returns to 1995, he picks Pete up through a window and slips away.
- The Slow Path: Having travelled back to 1995 to help Soichiro, PETE-13 opts to enter sleep mode for thirty years so that he can reunite with Soichiro when the latter takes his second cold sleep to 2025.
- Title Drop: Soichiro's opening narration talks about how when winter comes, his cat Pete keeps opening doors in the house, trying to find "the door into summer."
- Uncanny Valley: Most of the androids in 2025, including PETE-13, the cold sleep clinic nurses and the Guardian Manufacturing receptionists behave in a stiff, unnatural manner. Gradually subverted by PETE-13, who even learns to give Soichiro an geniuinely warm smile.
- Worthless Yellow Rocks: PETE-13 explains to a bewildered Soichiro that gold (along with nearly all precious metals) are practically worthless in 2025, having been replaced by digital currency. Professor Toi later provides Soichiro with dozens of gold bullions to take back to 1995, where it can be used to fund a younger Toi's time travel research and pay for patent attorney Sato's services.
