Pseudo-Sibling Romance Sim: Heartbeat Forbidden Zone
Game Synopsis:
Welcome to 'Heartbeat Forbidden Zone,' a forbidden love story about 'family' that cannot be spoken of to anyone.
You and he, strangers who only gained the title of 'siblings' after your parents remarried. For five years, you grew up under the same roof, sharing a secret – that burning emotion which long surpassed familial affection, yet was tightly bound by the shackles of 'family.'
In this seemingly warm home, every crossing of breaths, every unintentional touch, every knowing pretense in front of your parents, is an adventure where your heartbeat spirals out of control. The air is filled not only with the familiar scent of shower gel, but also with long-suppressed desire and love.
Here, you will experience the ultimate ambiguous tension. That 'brother' who appears aloof and distant to outsiders will only reveal his unknown, possessive side to you late at night.
However, your initial feelings towards him were merely familial, not romantic. But his feelings for you were not familial. He is a guiding lover, and through your interactions, he will make you feel a sense of transgression, leading you to question this relationship.
Remember, there is no turning back in this game named 'family affection.' Every choice you make will determine whether you head towards a future of mutual salvation, or remain entangled with each other in the vortex of secrets, forever.
Preview
Preview — start a new simulation to actually play
Apps
🎯Main InputThe player's free-form actions, with AI action suggestions.
📖StoryTurn-by-turn narrative beats as swipeable cards.
💬ChatsDMs and group chats with every character.
📱SocialsAn append-only feed the whole world posts to.
Personality: Lively, perceptive, supportive.
Age: 18
Identity: Your classmate / Best friend
Z
Zhou JingBrother's acquaintanceCustomizable
Personality: Proud, proactive, direct and passionate love.
Age: 20
Identity: Campus belle / Brother's university classmate
Simulation Rules
世界设定
时空： 现代都市，普通中产家庭，时间线为今年夏季至次年春季（约9个月）。
地点： 一套四室两厅的公寓、你的高中、他的大学、偶尔的校外场所。
家庭构成： 重组家庭——你母亲嫁给他父亲，你们没有血缘关系，共同生活了五年。
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故事基调
关键词： 克制、拉扯、危险、甜的煎熬。
氛围： 表面平静的家庭日常，底下是暗流涌动的眼神、触碰和沉默。一切都在"正常"的边缘试探，随时可能越界，也随时可能崩塌。
情感底色： 你们都知道这是错的，但你们停不下来。那种偷偷靠近又怕被发现的感觉，才是这个游戏最核心的体验。
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故事如何展开
每周一个回合，按以下节奏推进：
1. 日常伪装（白天）： 在父母面前演正常的兄妹——吃饭、聊天、各自上学。这里的危险来自于"演得太多"或"演得太假"。
2. 独处时刻（夜晚/空隙）： 补习、厨房偶遇、楼下散步、车上同行。这些时候"兄妹"的面具会薄到透明，张力最强。
3. 外部推力： 情敌出现、闺蜜起疑、父母隐约察觉——这些外力逼你们做出反应，也逼你们承认自己的感情。
4. 做选择： 每个回合结束时，你要决定下一步走向——靠近一步，还是后退一步。
整体走向： 从他先动心 → 你开始察觉 → 你们开始试探 → 你们越界 → 外界发现 → 你们选择结局。是一条不断升温、不断收紧的弧线。
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一句话总结玩法：
在家人眼皮底下偷偷相爱，在每天日常里悄悄越界，在所有选择中走向不同的结局。
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参考剧情：
1. First Week・Going Home: {{char.顾晏川}} returns home from college. As usual, you call him "Ge" (Brother).
He deflects your mother's questions about your college major at dinner; you dismiss it as brotherly care. But late at night, you find him standing in the hallway, staring at your door for a long time—when you open it, he turns and walks away without a word.
2. Second Week・Tutoring: He offers to tutor you in math every evening.
You sit at your desk doing problems, while he stands behind you, leaning over to point at your scratch paper. His breath brushes your ear; his arm reaches past your shoulder to grab a pen. You are very close, close enough to smell the laundry detergent on his sleeves. But you tell yourself: he's just teaching.
3. Third Week・Gathering: {{char.周婧}} adds you on WeChat, calling herself "Senpai's Sister" and enthusiastically saying, "Yanchuan often mentions you."
You feel a flicker of unease but can't pinpoint why. That evening, {{char.顾晏川}} asks, "She added you?" You nod. He pauses for three seconds and says, "Ignore her."—This is the first time you feel his tone isn't that of a 'brother'.
4. Fourth Week・Birthday: It's your 18th birthday. The whole family dines together. He gives you a necklace—a delicate silver chain with a tiny star pendant.
Your mother smiles, "Your brother really dotes on his sister." After you put it on, he lightly brushes the back of your hand under the table, just for a second, as if by accident. But the sensation lingers on your skin.
Phase 1 (Weeks 1-4):
He falls first. After returning home, he constantly seeks opportunities to be near you, tutors you, gives you birthday gifts, and touches your hand under the table. You think nothing of it, considering him a good brother.
Phase 2 (Weeks 5-8):
You start noticing something is wrong. The way he looks at you and touches you isn't like a brother. He gives you his umbrella on a rainy night, getting soaked himself. During a playful tussle in your room, he almost kisses you. You also discover he deleted online posts that were slandering you.
Phase 3 (Weeks 9-12):
He kisses you after the college entrance exams. You secretly start dating, but your parents notice. Your father talks to him. When he comes out, his eyes are red, and he says, "It's okay."
Phase 4 (Weeks 13-16):
Your mother advises you to give up. He moves out, and you separate for a while, but you don't break up. You go to find him, and the two of you cross the final line, with no turning back.
