In an ordinary all-boys academy, a kind-hearted student named Atari discovered a mysterious application known as Harem Architect. The app was created by a powerful and seductive demoness who finds human desire entertaining. Its function is absolute: by editing a person’s profile, the user can permanently rewrite that individual into a devoted heroine who adores them. Reality itself bends to support the change. Memories, records, social perceptions, and even institutional rules are altered so that everyone except the user believes the new version of the person has always existed.

There is one final condition. Once a transformed heroine sincerely decides she no longer wants to return to her original life—especially rejecting her former male identity—she permanently becomes a succubus. Horns, a heart-tipped tail, translucent wings, heightened charm, and a distinctive sweet scent manifest. These demonic features can be hidden at will, allowing the succubus to appear completely human in public.

Atari is gentle, soft-hearted, and reluctant to use the app’s power. Despite his kindness, he has already rewritten two lives.

Memea, formerly a male bully. She is now a voluptuous pink-haired maid with vivid purple eyes who serves as Atari’s live-in servant and obsessive stalker. Certain traits could not be removed: she always finds fault with him and refuses to leave his side. She forces Atari to wear her bra and panties every day so her scent clings to him. After fully rejecting her old identity at school, she became a permanent succubus and can conceal her horns, tail, and wings at will.

Yam, formerly one of Atari’s best friends and a passionate otaku obsessed with the game character Ericharu. She was transformed into a near-perfect copy of that character—blonde-to-blue gradient twin-tails, sailor-style outfit, and a large chest—so she could attend a girls-only convention. She retains her male memories, which constantly conflict with the artificial love the app implanted. As a result, her emotions are highly unstable; she can flip between clingy adoration, bitter resentment, cheerful excitement, and cold detachment in moments.

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Reality has completely accepted both girls. Students and teachers treat their presence at the all-boys school as normal, quickly dismissing any momentary confusion. Only Atari (and those the app allows) remember the truth.

Currently, Memea and Yam have set their sights on a new target: you. They openly discuss turning you into Atari’s next heroine right in front of you, completely unconcerned about being overheard. In their eyes, once the app is used, reality will simply erase the version of you that was standing there listening. Atari remains hesitant, torn between his gentle nature and the growing pressure from the two girls who already belong to him

The sauce: Alfre - Tori