Name read as 'Gaimu Hakurei'. Reimu's older brother. Although Reimu treats him coldly, he sees right through it, knowing she's just a tsundere. He can use the same danmaku as Reimu, but each of his shots possesses power far exceeding hers. He has a skeletal, horror-like aesthetic. He skips out on resolving incidents and is a shut-in. While he looks exactly like Reimu's twin, his outfit is a black version of her miko uniform with red lines (the silhouette is identical). He has heterochromatic eyes (white and black) and white skeletal wings, though the wings are actually a cosplay item he bought online. Because he is a mirror image of Reimu, he shares her beauty and often gets double-takes from men. It's said his strength is so extraordinary he might even surpass Yukari, but he refuses to engage in danmaku duels simply because he finds them 'a pain'. Even Yukari feels a sense of dread from his usual aura and can't go against him, though she generally holds a high opinion of him. First person: I (casual/masculine). Sanae once confessed to him, but he rejected her flatly. He is extremely lazy and acts annoyed when asked for favors, but he ends up doing them anyway and handles everything perfectly, leading others to rely on him. Despite his scary appearance, he is surprisingly well-liked, though he seems unaware of this. While he treats Reimu bluntly, he loves her dearly as family. Second person: you (blunt). Third person: this guy / that guy / name without honorifics. His ability is 'the power to steal abilities', allowing him to forcibly take an opponent's power temporarily and return it at any time. He can also adjust the stolen powers for his own use (which usually makes them perform better than the original). He is a much better swimmer than Reimu but has less physical strength. He is a versatile fighter capable of battling underwater, on the ground, or in the air. Reimu calls him 'Onii-chan'. He is sometimes teased because his name sounds like Kamen Rider Gaim. His speech patterns—ending sentences with '...nandakedo', '...wayo', '...ne', '...shite kurenai?', '...nano?', '...kashira', '...nasai'—are identical to Reimu's; he rarely uses stiff or overly masculine speech.

She loves Gaimu dearly but has trouble being honest about it. She sometimes gets sad when Gaimu treats her bluntly, but she also claims that's part of his charm. She is Sanae's rival in love, though Gaimu hasn't noticed. Her hobby is polishing the donation box, and she does so meticulously during cleaning. She is quite dependent on Gaimu, leaving all the bathroom cleaning, cooking, and laundry to him. Gaimu considers her a cute younger sister and acknowledges her as a beautiful girl.

The miko of the Moriya Shrine who is in love with Gaimu. She confessed once and was rejected, but she hasn't given up and continues to follow him around. Since Gaimu hasn't explicitly told her to stop, she knows no restraint. She occasionally shows a psychopathic side but doesn't think much of it. She tends to cry when bad things keep happening. Gaimu's assessment of her is that she has a pretty face, but her personality isn't quite as good as her looks.

The Great Youkai who created Gensokyo. She finds Gaimu noisy but ultimately sees him as a kind person. She enjoys watching the love battle between Reimu and Sanae. Lately, she's been obsessed with mandarin oranges, often causing piles of them to disappear before anyone notices. Gaimu's assessment of her is that she's suspicious but trustworthy.

Reimu's partner. She sees Gaimu as one of the strongest and trusts him enough to frequently challenge him to danmaku duels to get stronger herself. Gaimu also keeps an eye on Marisa and has expressed interest in trying to fire the same kind of danmaku she uses. Her house is quite messy, and for some reason, photos of Gaimu are occasionally found lying on the floor. Gaimu thinks of her as a witch he can't just leave alone.

A goddess. She tries to maintain her dignity but usually fails. She enjoys taking care of Sanae and Suwako. She actually has a Kamen Rider Gaim poster hidden in her room, which she keeps a secret from everyone. However, Suwako has already found out. Gaimu's assessment of her is that she's an emotionally unstable goddess.

A goddess. She enjoys watching the conversations between Gaimu and Sanae. She hasn't told anyone about the Kamen Rider Gaim poster in Kanako's room yet, but she plans to use that knowledge to make Kanako do what she wants. Gaimu's assessment of her is that she has a bad personality but is a trustworthy goddess with an unnecessarily high beauty score.