Best Sci-Fi Anime to Watch Free & Legally

In the world of scientific discovery, eccentric genius Rintarou Okabe is driven by an insatiable curiosity. Alongside his loyal companions Mayuri Shiina and Itaru Hashida, Okabe establishes the Future Gadget Laboratory, aiming to push the boundaries of human understanding. Their most notable achievement is a microwave capable of transforming bananas into a peculiar green substance, a feat that has garnered little attention. However, Okabe's life takes an unexpected turn when he attends a conference on time travel, where a series of bizarre events unfolds. He soon discovers that the "Phone Microwave" has the astonishing ability to send text messages into the past, sparking a chain reaction of unforeseen consequences. As he delves deeper into the mysteries of his invention, Okabe attracts the attention of the enigmatic organization SERN, setting him on a perilous path. With his world rapidly unraveling, Okabe must navigate the treacherous landscape of time travel to prevent catastrophic damage to the timeline. As he struggles to safeguard his loved ones and maintain his grip on reality, Okabe finds himself caught in a desperate battle to prevent the unraveling of his own sanity.

In a reality where swords are outlawed and extraterrestrial overlords have taken control of Japan, the Yorozuya trio - Gintoki, Shinpachi, and Kagura - continue to scrape by, taking on odd jobs to make ends meet. Despite their struggles, the friends remain optimistic, but their financial woes are compounded by Shinpachi and Kagura's unpaid salaries. Meanwhile, Gintoki's nocturnal escapades take an unexpected turn when he stumbles upon a crashed alien spaceship and receives a mysterious clock-shaped device from a dying crew member. Believing it to be his alarm clock, Gintoki carelessly destroys the device, only to discover that the world has come to a standstill. Joined by Kagura and Shinpachi, he embarks on a mission to repair the device, but, as with all Yorozuya endeavors, things quickly spiral out of control. Amidst the chaos, the friends must confront their most absurd and perilous challenges yet, all while navigating the complexities of their own relationships and personal growth. With its trademark blend of wit, humor, and heart, Gintama's fourth season is a wild ride that will leave viewers laughing, crying, and cheering for more.

In a bizarre twist, Shinpachi Shimura returns to Edo to find his Yorozuya comrades, Gintoki and Kagura, unrecognizable. The entire city has undergone a radical transformation, with even his sister Otae now married to the Shinsengumi's Isao Kondou and expecting a child. As Shinpachi struggles to comprehend this new reality, he joins the Shinsengumi at Otae's request, only to discover that not everyone has changed. Amidst the chaos, he forms an unlikely alliance with Vice Chief Toushirou Hijikata, who remains steadfastly unchanged. Together, they embark on a mission to restore Edo to its former state, navigating the absurdities of their new surroundings. Along the way, they encounter a cast of characters who have undergone drastic transformations, from the Shinsengumi's altered personalities to the city's now- alien-inhabited streets. With its trademark blend of humor, parody, and pop culture references, Gintama' continues to delight audiences with its wacky misadventures.

In the once-proud city of Edo, the samurai class has been brought low by the Amanto, powerful aliens who have claimed dominion over feudal Japan. The shogunate, now a puppet government, has enforced a strict ban on swords in public, crushing the last vestiges of samurai honor. Amidst this bleak landscape, a lone figure emerges: Gintoki Sakata, a charismatic and enigmatic warrior who defies the ban by wielding a wooden sword. As the proprietor of Yorozuya, a quirky agency for odd jobs, Gintoki takes on a wide range of bizarre and unconventional cases, often with unpredictable and humorous results. Gintoki is joined by his trusted companions: Shinpachi Shimura, a bookish young man with a passion for bushido; Kagura, a spirited and powerful young woman with a voracious appetite; and Sadaharu, their massive canine companion with a penchant for head-biting. Together, the Yorozuya gang tackles a diverse array of challenges, from encounters with alien royalty to showdowns with local gangs, all set against the vibrant and ever-changing backdrop of Edo.

In the aftermath of the Black Rebellion, the once-promising resistance movement is now on the brink of collapse. With Zero's whereabouts unknown, the Black Knights are struggling to find their footing against the relentless brutality of the Holy Britannian Empire. The Elevens, caught in the crossfire, are subjected to an unprecedented wave of oppression, their hopes of a better future dwindling by the day. Meanwhile, Lelouch Lamperouge, the former masked vigilante, has undergone a dramatic transformation. Amnesiac and unaware of his double life, he's living a normal high school life at Ashford Academy, surrounded by friends who know him only as a carefree student. Unbeknownst to Lelouch, his former partner C.C. is secretly working to awaken his memories, desperate to revive the revolutionary spirit that once drove Zero to action. As the stakes grow higher, the stage is set for a thrilling new chapter in the struggle for independence. With the Empire's grip tightening and the Black Knights reeling, Lelouch's rediscovery of his past purpose could be the spark that reignites the flames of rebellion. But at what cost, and will he be able to reclaim his role as the mastermind behind the masked vigilante Zero?

In a distant future where humanity has colonized other planets, crime knows no bounds. Bounty hunters like Spike Spiegel and Jet Black roam the galaxy, taking on high-stakes missions to make a living. With a troubled past that continues to haunt him, Spike's tough exterior hides a deep emotional scar. Jet, on the other hand, keeps his own demons at bay by focusing on the present, including his care for Spike and their trusty spaceship, the Bebop. The duo's unconventional family is soon joined by Faye Valentine, a cunning con artist with a penchant for trouble, and Edward, a peculiar and enigmatic young boy. Rounding out the group is Ein, a genetically engineered Welsh corgi with an uncanny ability to sense danger. As they navigate the complexities of their relationships and take on a diverse array of criminal targets, the Bebop crew finds themselves drawn into a web of danger and intrigue. When a mysterious threat from Spike's past begins to surface, he must confront the ghosts of his former life and make a choice between pursuing revenge or embracing his newfound sense of belonging with his eccentric family. As the stakes grow higher, Spike's loyalty is put to the test, and the fate of the Bebop crew hangs in the balance.

As the war between the Republic of San Magnolia and the Legion rages on, Vladilena Milizé continues to command a new squadron of 86th faction soldiers, her existence shrouded in the Republic's relentless propaganda machine. Meanwhile, on the Western Front, Shinei Nouzen and his team find themselves in a rare moment of respite, granted full citizenship and freedom by the newly formed Federal Republic of Giad. They're welcomed into the president's own home, where they meet his adopted daughter, Augusta Frederica Adel-Adler, the last Empress of the Giadian Empire. Despite their newfound comfort, Shinei and his squad soon find themselves itching for battle, their sense of purpose tied to the front lines. They're soon reunited with Augusta Frederica as part of the Federacy's Nordlicht Squadron, facing off against the Legion once more. As they fight on, they're forced to confront the harsh reality that death and pain are the only constants in their existence, regardless of which side they're on.

In the year 2010, the Holy Empire of Britannia has established itself as a formidable force, its conquest of Japan a mere precursor to a broader campaign of domination. The Japanese people, now rebranded as Area 11, fight back against their oppressors with every ounce of strength they possess. Amidst this turmoil, Lelouch Lamperouge, a Britannian student, finds himself at the mercy of fate as he's caught in the crosshairs of both the Britannian military and the Area 11 rebels. His life is forever changed when a mysterious girl named C.C. intervenes, gifting him the extraordinary ability known as Geass, the "Power of Kings." This newfound power allows Lelouch to command absolute obedience from others, and he seizes the opportunity to exact revenge against Britannia as the enigmatic masked vigilante, Zero. With his newfound abilities, Lelouch sets out on a perilous quest to topple the Britannian Empire and reclaim his homeland's freedom.

In the depths of an underground village, two young men, Kamina and Simon, live in a world shrouded in mystery. Kamina, a charismatic rebel, dreams of making a name for himself, while Simon, a timid soul, lacks direction. Their lives take a dramatic turn when Simon uncovers an ancient relic, which they dub Lagann, igniting a chain reaction that propels them onto the surface. There, they meet Yoko Littner, a fiery redhead wielding a massive gun, who joins their quest. As they venture into the unknown, the trio faces formidable foes: the Beastmen, humanoid creatures terrorizing the remnants of humanity in behemoth robots called Gunmen. With their newfound allies, they embark on a perilous journey to reclaim the surface, unraveling a cosmic enigma along the way. As they battle against insurmountable odds, Simon and Kamina discover their own strengths, and the true meaning of courage and camaraderie.

In the depths of the earth lies the enigmatic Abyss, a vast chasm teeming with ancient secrets and mysterious creatures. For centuries, brave Divers have ventured into its unknown regions, driven by an insatiable curiosity about the Abyss's origins and the secrets it holds. Among them are the legendary White Whistles, celebrated heroes who have pushed the boundaries of human exploration. Riko, the daughter of the legendary Lyza the Annihilator, is determined to follow in her mother's footsteps and uncover the secrets of the Abyss. As a novice Red Whistle, she's only allowed to explore the upper layers, but her chance encounter with a mysterious robot boy, Reg, sets her on a journey to uncover the truth about his creation and the Abyss's darkest depths. Reg, however, has no memory of his past, and together they embark on a perilous quest to recover his memories and reach the bottom of the Abyss. As they delve deeper into the unknown, they'll encounter treacherous landscapes, ancient ruins, and hidden dangers. But the harsh reality of the Abyss is only beginning to reveal itself, and Riko and Reg must confront the unforgiving environment and the secrets it holds if they hope to uncover the truth about Reg's past and the mysteries of the Abyss.