The Main Cast
An anxious, red-headed youth who just moved to Enoshima island with his grandmother, Keito. He is probably the main character.
- Audience Surrogate: At the end of each episode, he takes on a narrative role; the narrations show that the events of Tsuritama have already happened and Yuki is reflecting on all of the events as the audience watches them unfold.
- But Not Too Foreign: He's one quarter-French and three quarters-Japanese, he gets his French blood from his grandmother, Kate.
- Demon Head: When he gets really nervous his face becomes like this, but he can't help it. It's really very embarrassing for him.
- Get a Hold of Yourself, Man!: Does this to Haru after he makes everyone leave Enoshima to protect them from Urara and he falls into a state where he believes everything is pointless in trying to stop Urara, a slap from Yuki snaps him out of it.
- New Transfer Student: He's transferred many times, and because of this and his shyness, he never really made any friends.
- Not Good with People: He gradually gets better, but still has outbursts of social anxiety.
- Parental Abandonment: It's never mentioned what happened to them, but for one reason or another, Yuki has been raised by his grandmother.
- Shrinking Violet: At first.
- Took a Level in Badass: Watch and see.
An alien from an unspecified planet who decided to become Yuki's friend and fish together, with or without Yuki's agreement. He transfers to Yuki's class on the same day as him, and even moves into his house. Claims to be saving the world from...something.
- Alien Among Us
- Animorphism: Can turn into a betta fish. Quite possibly, the fish is his default form.
- Bishōnen: Almost borders on Dude Looks Like a Lady.
- Blue and Orange Morality: Certainly well-intentioned enough though. He wants to understand how humans think and feel, but he doesn't understand at first that people don't appreciate being mind-controlled even though it makes them cooperate, that Death Is a Sad Thing, that "I'm sorry" doesn't solve everything, and he only feels sorrow for the first time while on Earth.
- Cry Cute
- Heroic BSoD/Freak Out!: He absolutely loses it after Coco seemingly dies.
- Heroes Want Redheads: Turns out to be a plot point: Aliens love the colour red.
- Human Aliens: The vast majority of the time.
- Large Ham:Haru: Skyyyy....TREEEEEEE!
- Fish out of Water: Heh... literally.
- Mind-Control Device: Uses an ordinary water gun. His species can communicate through water, but when they use their powers on Earthlings, it ends up as mind control.
- New Transfer Student
- No Sense of Personal Space
- No Social Skills: A result of being a Fish out of Water.
- Older Than They Look: Haru is over one hundred years old, since he states once that he'd been looking for Urara for a century.
- Purple Eyes: As with the other aliens, they help him stand out from normal humans.
- Sibling Yin-Yang: Haru is much more eccentric, jovial, and energetic than his sister, Coco.
The "Fishing Prince" of Enoshima who has been a dedicated fisher since he was a child. He teaches Yuki and Haru to fish; a real test of his patience. Seems to have some issues with his well-meaning father. He is also in Yuki and Haru's class.
- Anime Hair: That wild hair could be mistaken for an afro. Subverted when he's made to get a hair cut, but shown to have grown it back out in the epilogue.
- Big Brother Instinct: To his ten-year-old sister, Sakura.
- Defrosting Fishing Prince
- Embarrassing Nickname: Do NOT call him a "Prince" in class.
- Jerk with a Heart of Gold
- Missing Mom: She died two years before the start of the story and he is not happy about his father falling in love with another woman.
- My God, What Have I Done?: Occurs after slapping Sakura and bringing her to tears.
- Only Sane Man
- Stoic Spectacles
- Sugar-and-Ice Personality: Natsuki acts coldly towards strangers and people who get on his bad side—like his father and Akira—but gently towards those he cares for, like his sister, Yuki and Haru. His shift in tone from almost callously indifferent to very warm when speaking to Yuki over the course of the first four episodes really illustrates this aspect of him.
Akira Agarkar Yamada
A mysterious half-Indian working for an even more mysterious organization known as "Duck." He is interested in Haru's motive for coming to Earth, and keeps a close eye on him. He is always with his co-worker, a duck named Tapioca, and can understand her speech. He later transfers into class with the others, despite being twenty-five years old.
- But Not Too Foreign: He's half-Indian and half-Japanese.
- The Comically Serious: At one point he even seems to break down and be in physical pain from a joke the old priest made.
- HeelFace Turn: Not that he was ever evil.
- Ineffectual Loner: Natsuki thinks he is one of these for following them around. He later becomes a true member of the group.
- Jerk with a Heart of Gold
- Let's Get Dangerous!: Yoga...
- New Transfer Student: And when he transfers, his age and refusal to leave his pet duck at home makes him even more of a spectacle than Yuki's awkwardness or Haru's coming to class with a fishing rod and introducing himself as an alien.
- Nice Turban
- Not So Stoic: He normally has a calm-disposition in the world strangeness and silliness around him. However, he does break his stoicism from time to time for laughs.
- Older Than They Look: He's 25-years-old, being eight years older than Yuki, Haru, and Natsuki, but he doesn't look older than 17 when with them, just really tall.
- Speaks fluent duck
- Trademark Favourite Food: He is often seen eating a bowl of whitebait curry, courtesy of D.U.C.K.
- Tsundere: When it comes to denying that he wants friends.
A white duck who works for the international extraterrestrial-investigation organization Duck. Although she can only quack, she is as intelligent as a human and very dedicated to her cause.
- Ambiguous Gender
- Cross-Dressing Voices: She's voiced by Akira's seiyuu and VA.
- Intellectual Animal
- Nearly Normal Animal
- Non-Human Sidekick
- Speech-Impaired Animal: Quack. Quack.
- Ridiculously Cute Critter: To the citizens of Enoshima.
Major Secondary Characters
Yuki's grandmother. A French horticulturalist and a traveler, she is patient, motherly, and wise, and above all, very laid-back to contrast Yuki's tightly-wound mannerisms. Seems to be a good judge of character.
- Cool Old Lady: Without a doubt. This woman let a self-proclaimed alien live in her house without losing her kind smile for a moment.
- Eccentric Mentor: The best kind of eccentric.
- Ill Girl: Comes of being over seventy.
- Incurable Cough of Death: Subverted. She turns out fine.
- Innocent Flower Woman
- Lady of Adventure: A minor example. She doesn't go hunting for dragons, but she did like to move around a lot before probably settling down in Enoshima.
- Spell My Name with an "S": Kate or Keito?
- Team Mom: To Yuki and Haru at least. She gives a lot of good advice.
Haru's sister. Still a Cloud Cuckoolander like the rest of her species, but much more serious and purpose-driven and less happy-go-lucky and touristy than her brother. Isn't sure Yuki is the man for the job.
- Cloud Cuckoolander
- Animorphism: She's sometimes a fish. Much more often than Haru.
- Human Aliens
- Multicolored Hair: Dem blue flower splotches.
- Purple Eyes: Like with the other aliens, they help her stand out more from normal humans.
- Rummage Sale Reject: Aliens sure love dem polka-dots and stiff round collars. (Sakura thinks her outfit is cute though.)
- Sibling Yin-Yang
That angry guy in a pink shirt who usually hangs around in the bait shop. He owns a fishing boat that Yuki, Haru and Natsuki work on during summer vacation, and is actually not always angry or scary. In love with Misaki.
- Bear Hug: With Yuki, Haru and Natsuki
- Big Brother Mentor: To Yuki and co.
- Big "YES!": Walks out of the shop and starts hollering and hooraying outside with his back to the camera whenever Misaki compliments him.
- Boisterous Bruiser: More of this than actually angry. Though he's not actually a big guy.
- Disney Death: Thankfully averted.
- Gender-Blender Name
- Hen Pecked Husband: Who knew sweet little Misaki had a mean side?
- Real Men Wear Pink: That shirt.
- Testosterone Poisoning