One day at the local dump ever-accident prone schoolboy Nobita Nobi (voiced by Megumi Ohara) discovers a withered little tree. He brings it home to show Doraemon (Wasabi Mizuta), his faithful time-travelling robot cat, who naturally uses one of his handy gizmos to revive the ailing sapling. To their surprise the tiny tree comes to life as Kibo (Takuya Yoshikoshi), a super-strong, perpetually cheerful and energetic green imp whom Nobita duly adopts as a little brother. Kibo's helpful nature and cheery disposition quickly endear him to Nobita's parents and friends Shizuka (Yumi Kakazu), Suneo (Tomokazu Seki) and Jian (Subaru Kimura).
Like any plant, Kibo thrives on sunshine and water. Nobita and Doraemon ensure he has plenty of both. When the trash-clogged forest starts affecting Kibo's health, Doraemon clears it up using his latest gadget: the Garbage Spray. It brings trash to life that then returns to its owner. Whereupon the kids discover the forest holds a gateway to an alien world. Populated by plantlike lifeforms that for quite some time have been secretly observing planet Earth. Appalled by humanity's disrespect for the environment they summon Nobita and his friends before the Intergalactic Plant Council led by feisty young eco-warrior Princess Lire (Maki Horikata). There Nobita is horrified to learn that Lire's chief minister Shiraa (Chikao Otsuka) wants to turn Kibo into a super-weapon to wipe out the Earth.
Environmental issues have long been a strong theme in Japanese children's animation, whether in auteur-driven films like the work of Osamu Tezuka and Hayao Miyazaki or more disposable fare. Japan's most popular children's anime franchise: Doraemon is no exception. The broccoli-haired talking plush toy Kibo (whose dialogue, much like Pikachu from Pokemon, consists of repeating his name endlessly) previously appeared sixteen years earlier in Doraemon: Nobita and the Kingdom of Clouds (1992). However, Doraemon: Nobita and the Green Giant Legend is no remake. Based on the eight-part story serialized in the manga created by Fujiko-Fujio (the joint pseudonym for writer/artists Hiroshi Fujimmoto and Motoo Abiko) combines ever-pertinent anti-pollution themes with traditional Shintoist beliefs about spirits inhabiting and binding all living things in the universe together. Opening in ominous fashion with alien voice-overs scrutinizing humanity the film evokes classic cautionary sci-fi fables from the Fifties like The Day the Earth Stood Still (1951) or Japan's own Warning from Space (1956) a.k.a. The Mysterious Satellite. In those films more often than not a woman or child represent the more self-aware, thoughtful and caring side of a humanity otherwise blundering recklessly towards destruction in the name of progress. Here it is good old nice but dim Nobita (whose greater sin, in the eyes of a workaholic Japanese audience, would be his laziness) who embodies that role. Nobita's big brotherly bond with Kibo serves as an extended metaphor for Japan's traditionally patient, empathetic and mutually nurturing relationship with nature.
Too often this particular sub-genre in animation tends to be overly preachy or simplistic. Take for example: Ferngully: The Last Rainforest (1992), Once Upon a Forest (1993) or worst of all Don Bluth's abysmal A Troll in Central Park (1994). However, Nobita and the Green Giant Legend manages to interweave its eco themes into a compelling adventure story that hits all of the series' familiar beats: slapstick comedy, well observed character interaction and eye-catching, imaginative sci-fi spectacle. It manages to get its message across without making kids feel like they are being lectured. In fact far from a hand-wringing sermon about the environment the central message is that while humanity makes mistakes, learning from them is what makes us human. For her part Princess Lire (sort of a spikier Nausicäa right down to the cool sky-cycle) believes the galactic forest belongs exclusively to plant people until she and Nobita encounter Tama (Teppei Arita) and Rock (Yoko Tsuchiya), two adorable little elves (lot of cute characters in this movie) who explain that the planet sustains all life.
The film adheres to the typical structure of a Doraemon adventure, with the first half centred on surreal domestic hijinks before the second act transports the kids to a richly detailed alien world. It creates a memorable environment of floating trees, giant vegetable homes and cuddly plant lifeforms including a wise old mushroom wizard, mixing traditional 2D animation with quirky 3D sequences. These mimic claymation, oil paintings and cut-out animation creating an almost tactile sensation of delving into a pop-up book. The animation is remarkably fluid. Each character seems vividly alive. Plus the film includes several excellent aerial action sequences worthy of Miyazaki. Interestingly the plot lifts several notable motifs from Hollywood science fiction films including, believe it or not, the senate debate from Star Wars - Episode One: The Phantom Menace (1999). Which it manages to invest with more compelling drama and imaginative spectacle. On top of that the dense, carefully balanced eco-system depicted here prefigures the similarly eye-popping plant-based world James Cameron created with Avatar (2009). After the story takes a surprisingly apocalyptic left turn with planet Earth overrun by plant life and malevolent giant green blob creatures, the third act finds hope in youthful determination. Plus the willingness to ponder why we constantly view those that disagree with us as enemies? It ends on a tear-jerking note that invokes E.T. The Extra-Terrestrial (1982) though of course Doraemon would return.