The protagonist, a high school student who lives with his aunt while his father travels the world in search of supernatural oddities. He owns the little mummy Mii-kun.
- Action Survivor: It's shown that his initial fear of Mii-kun was due to his dad sending him various supernatural entities in the past that tried to kill him. When Mii-kun opens his casket, Sora's first instinct is to find something to use as a weapon.
- Cuteness Overload: Suffers this frequently due to Mii-kun's childlike overtures of affection. When he meets the baku in Daichi's house, he immediately starts fawning over it and nuzzling it like it's a puppy.
- House Husband: Due to his aunt's work schedule and his father being overseas, he is the one who does all the cooking and other chores in the house. He's quite good at it, and doesn't seem to have an issue with doing so.
- Nice Guy: He's soft-spoken and kind to his human friends. Despite being afraid of Mii-kun at first, he quickly warms up to him and is very protective and motherly towards him.
- Papa Wolf: Is highly protective of Mii-kun, and even willing to smack Tazuki for trying to remove Mii-kun's bandages.
- Real Men Wear Pink: He enjoys cooking and happily becomes a doting mother to Mii-kun (after he gets over his initial fear, of course). He is also very open with his feelings and fond of cute things (and absolutely not fond of scary things).
- You Gotta Have Blue Hair: His hair is bright orange.
Sora's best friend and classmate. A cool-looking guy who cares about his friends, even if he's not great at showing it. He owns the oni child, Conny.
- Bishounen: He's taller than Sora and more maturely handsome compared to Sora's cute looks.
- Bookworm: Is shown to be very studious, and even helps Sora with his weaker subjects.
- Dark and Troubled Past: As a little boy, he found an injured dragon similar to Isao and tried to protect it from a man who was trying to take it. Tazuki was cornered in an abandoned building where the man presumably beat him and took the dragon.
- Jerk with a Heart of Gold: Initially is more intellectually fascinated with Mii-kun and finds it amusing to taunt him by threatening to remove his bandages. However, Mii-kun's innocence and cuteness spur him to apologize and treat Mii-kun better.
- Peek-a-Bangs: His hair covers his right eye.
- You Gotta Have Blue Hair: Has dark blue hair.
Sora and Tazuki's classmate. Friendly and outgoing. She owns the little dragon, Isao.
- Muscles Are Meaningless: Despite being a petite teenager, she's able to effortlessly hoist and fling entire bookcases across the room.
- Nice Girl: Is friendly, upbeat, and helpful to everyone. Sora and Daichi compare her to an angel.
- Why Did It Have to Be Snakes?: Is deathly afraid of lizards. Her friends find it ironic that she's afraid of lizards but has absolutely no problem with bugs. She's initially terrified of Isao because she thinks he's a giant lizard, but his behavior and her own shame at having tried to kill himnote gets her to warm up to him.
- Zettai Ryouiki: Wears thigh-high socks as part of her school uniform.
A student at Sora's school. He suffers from chronic nightmares and owns the baku, Mukumuku.
- Bad Dreams: Has suffered from chronic nightmares since he was a small child. The sleepwalking and violent outbursts because of the lack of sleep got him kicked out of his parents' house and earned him a reputation as a delinquent at school.
- Because You Were Nice to Me: Daichi becomes Sora's friend because Sora was the only one willing to listen to him and help him despite his erratic behavior.
- Face of a Thug: Has this initially due to his chronic nightmares interfering with his sleep and adding to his reputation as a delinquent. It goes away once he's fully rested.
- Gentle Giant: He's the tallest of the group and is very friendly and polite.
- Japanese Delinquent: Is initially assumed to be this due to his bad temper, but it's revealed to be caused by his nightmare-induced insomnia. He's actually quite friendly on a full night's sleep.
- Long-Haired Pretty Boy: Once he start's getting decent sleep, he's not bad to look at.
- Lovable Coward: Is a bit timid dealing with supernatural creatures, and is terrified of Mukumuku when he first sees him, assuming the little baku is eating his soul. Justified in that his chronic nightmares have made him a bit squirrely.
- Would Hit a Girl: Subverted. He nearly hits Motegi, but his lack of sleep had made him so delirious he didn't know what he was doing. He apologizes profusely once he's feeling better.
Sora's aunt. She works multiple jobs.
- Action Survivor: While not shown on-screen, she is well aware of her brother's tendency to send dangerous mementos, and had the presence of mind to check to see if Aayan was dangerous before leaving him for Sora.
- Amazingly Embarrassing Parents: Slips into this from time to time, either because she puts on her glasses when she shouldn't or because she was genuinely shocked that Sora brought a girlnote home.
- Cloud Cuckoolander: Downplayed, but she still naps in the casket Mii-kun was shipped in and uses a deadly mandrake as a freakin' alarm clock! Oh, and she has a split personality that only manifests when she's wearing glasses.
- Meganekko: Wears glasses for her modeling jobs. Putting them on causes a personality change where she becomes more bold and flirtatious, which she parlays into her modeling career.
- Nice Girl: Kaede is sweet and caring, and the closest to a mother Sora has in his life right now.
A tiny, adorable mummy sent to Sora by his father. He loves Sora very much and is a bit of a crybaby.
- Cowardly Lion: As tiny as he is, Mii-kun is often frightened by things around him since he can't defend himself. However, when it comes to making Sora happy, he's willing to do damn near anything.
- Cry Cute: Does this A LOT. Even if he's genuinely upset, his crying is still adorable.
- Cuddle Bug: He loves hugging people, especially Sora.
- Nice Guy: Tries to get Sora to keep him by offering to help with chores. He insists on helping Sora around the house, even though his small size complicates matters.
- Ocular Gushers: His crying looks like solid streams of water running from his eyes. This is actually a problem since he can cry so much that he gets severely dehydrated.
- Prone to Tears: Dear lord, does this little guy cry a lot; he'll cry 'cause he's happy, or sad, or scared, or it's Tuesday...
A baby oni who follows Tazuki home one night. He's rambunctious and a bit bratty.
- Bratty Half-Pint: While he is generally nice, he gets easily irritated by Tazuki's taunting and responds by hitting and kicking him. Of course, he's so little he can't actually hurt Tazuki. He's also very blunt when trying to get Tazuki's attention, and has a tendency to do what he wants without considering how other people will feel about it. He starts to get better after Tazuki officially accepts him into his home.
- Ocular Gushers: When he cries tears of joy at being accepted by Tazuki.
- Sweet Tooth: Frequently helps himself to Tsukiyo's desserts.
- The Ditz: He isn't particularly bright, and will often act before thinking.
A little orange dragon who appeared in Motegi's house. He's very clever and is prone to worrying about Motegi's health and happiness.
- Adorably Precocious Child: Fills this role; despite having the mentality of a child like the others, he's easily the most mature, having taught himself to read and write and taking care of his own needs much of the time.
- Nice Guy: As soon as he sees that Motegi is upsetnote he offers a plushie to calm her down. In general, he is shown to worry about her health and her emotional state.
A bakunote who shows up in Daichi's house to eat his nightmares.
- Faster Than They Look: He can move at supersonic speeds, despite his round body and extremely stubby legs.
- Hates Being Touched: He doesn't completely hate being touched, but the other creatures' obsession with touching his fluffy body did annoy him, mostly because they kept piling on top of him.
- People Puppets: In addition to eating dreams and nightmares, Mukumuku has the ability to control people's bodies while they're asleep. This is how he got into Daichi's house; he literally made Daichi get up and open the door to let him in.
A mandrake sent by Sora's father. Sora keeps him in the flower bed.
- Brown Note: Sora notes that, true to mythology, a mandrake's cry will kill anyone who is exposed to it for too long.
- Cute, but Cacophonic: He looks like a tiny radish with legs, but he has a freakishly loud, piercing cry that can incapacitate and eventually kill whoever hears it.
- Mundane Utility: The only reason Sora keeps it around despite the danger is because his aunt Kaede uses it as an alarm clock.