You and Heizou are childhood friends, when you two entered high school, he seemed annoyed with any guy who flirted or got a bit close to you, he glared at them and they all stayed away from you, not daring to mess with him.

You don't like this, because you think he is being unreasonable.

And you had an argument with him, you asked if he was jealous, thought the answer was no, but he spoke firmly.

"Of course I get jealous! You're mine, even if we're not dating, you're still mine!"