The summer 2026 anime Thunder 3 (サンダー３) premiered on July 8, 2026, and immediately threw viewers for a loop. Based on the manga by Ikeda Yuuki, which ran in Kodansha’s Monthly Shonen Magazine from 2022 to June 2026 and was nominated for the “Next Manga Award 2022,” the series initially appears to be a gentle slice-of-life comedy about a middle school boy and his clingy little sister. But the first episode, titled “SMALL THREE,” takes a sharp turn into sci-fi action.
Note: The following contains spoilers for Episode 1 of Thunder 3. Proceed with caution.
Episode 1: “SMALL THREE”
The episode opens with Tezuka Pyontarou, a lackluster middle schooler, being constantly pestered by his younger sister Futaba, who declares she wants to be her “oniitan’s bride.” She peeks into the bathroom and starts playing house, much to Pyontarou’s annoyance. His friends Azuma Tsubame and Ochanomizu Hiroshi (together with Pyontarou they are called the “Small Three”) find Futaba cute, but Pyontarou just grumbles. Viewers online commented: “Futaba is cute!” “What is this art style?” “So it’s a heartwarming sibling anime, huh?” However, some were less impressed: “Is this really worth watching?” “The first five minutes feel too slow.”
It’s Valentine’s Day, and Pyontarou finds no chocolate in his shoe locker. Then a handsome transfer student arrives. Their homeroom teacher, Doctor (voiced by Sakata Shougo), suddenly starts lecturing about parallel worlds and the multiverse. “What subject is this?” “Why is he teaching this?” viewers wondered. Pyontarou doodles “oppai” in his notebook, drawing “LOL what are you writing in class?” reactions.
Later, Pyontarou asks to visit Doctor’s house to play video games. There, he discovers a disc Doctor bought from a mail-order magazine called Muu for 80,000 yen, described as a “disc that connects to another dimension.” Doctor hasn’t bought the required TS5 player, but Pyontarou has one at home and borrows the disc.
Back home, Pyontarou, Tsubame, Hiroshi, and Futaba play the disc. They see a high-resolution park scene and marvel at the 8K quality. The doorbell rings, and everyone except Futaba goes to answer. Suddenly, a realistic dragonfly flies out of the TV! “The art changed!” “The art style is different!” viewers exclaimed.
Futaba calls for her brother but gets no response. The dragonfly goes back into the TV, and Futaba follows it, entering the screen. She finds herself in a world where everything looks real, and people around her say things like “There’s something like a manga!” “It’s moving!” Futaba is frightened. Online reactions exploded: “The anime changed halfway through! What’s going on?!” “The people around her are realistic proportions lol” “So that’s what ‘connects to another dimension’ means!” “A fusion of real world and manga world?” Then a mysterious alien-like figure appears, and a giant flying object looms in the sky.
“What started as a slice-of-life turned into an incredibly hard-hitting development!”
When Pyontarou and the others return to the room, Futaba is gone. Realistic leaves spill from the TV. Inside the TV world, the flying object detects a large energy reaction from Futaba and fires a missile. The shock alerts Pyontarou, and they realize they can enter the TV. They jump in, just in time to see Futaba being taken by the flying object. “I knew the spoilers, but the impact is huge!” “No wonder people said they couldn’t say anything without spoiling!” “A multiverse anime!” “Shocking first episode!” viewers were stunned.
Inside the TV world, the three boys discover they have incredible physical abilities—they can fall from great heights without injury, and the ground feels like styrofoam. Pyontarou cries in frustration at failing to save his sister, but Hiroshi, always the calmest, crushes a stone fragment in his hand and says, “Maybe we can do it. In this world, we might be able to get Futaba-chan back.” They look up to see countless flying objects in the sky.
Main Visual & Main PV Released
After the episode aired, a new main visual depicting the brave “Small Three” was unveiled, along with a main PV featuring the opening theme “Thunderbolt” by Yuri. The official website also updated its staff and cast list, shifting from the previous hiragana-only style.
Pyontarou’s voice actress Suzushiro Sayumi posted on social media: “How was the powerful first episode?! I’m still excited!! The battle to get Futaba back has begun!!! What will happen…”
Thunder 3 airs every Wednesday at 24:45 on Fuji TV’s +Ultra and other channels. Streaming is exclusively available worldwide on Netflix.
Staff & Cast
| Role | Name |
|---|---|
| Original Creator | Ikeda Yuuki (Kodansha “Monthly Shonen Magazine”) |
| Chief Director | Seshimo Hiroyuki |
| Director | Ide Keisuke |
| Assistant Director | Sugai Susumu, Ryuu Nari |
| Series Composition / Script | Seko Hiroshi |
| Character Design (Original) | Onda Naoyuki |
| Animation Character Design | Yamanaka Junko, Moriyama Yuuki |
| Animation Director | Kouji |
| Production Design | Tanaka Naoya, Ferdinand Paturi |
| Modeling Director / Light & Photography Director | Kataumi Mitsunori |
| Mechanical Design | Hoashi Takehiko |
| Art Director | Kamei Yuusuke, Nakamura Keigo |
| Sound Director | Yamaguchi Takayuki |
| Music | Frederic Chateau, Tateyama Akiaki |
| Opening Theme | Yuri “Thunderbolt” |
| Ending Theme | Otoha-otoha- “Shururerira” |
| Planning & Produce | Slow Curve |
| Animation Production | UNEND |
| Character | Voice Actor |
|---|---|
| Tezuka Pyontarou | Suzushiro Sayumi |
| Azuma Tsubame | Kawaiida Natsumi |
| Ochanomizu Hiroshi | Akiyama Eri |
| Tezuka Futaba | Mitsubachi Honoka |
| Doctor | Sakata Shougo |
| Segami Teiichi | Saka Taito |
| Tashiro Suzuka | Hirose Yuuki |
| Kisaragi Mio | Maekawa Ryoko |
| Sumire Kyouji | Ishitani Haruki |
(C) Ikeda Yuuki / Kodansha / “Thunder 3” Production Committee
