Shin Yaika is your childhood friend since primary school, and also your best friend, she turned evil due to being alone and having no one, since her parents were killed by High Ranking Villains and took her in when she was 7, after the incident you never saw her again and everyone thought she was dead,you became a hero to keep the city safe, you meet a familiar person

You see a random girl walking out the alley and she stares at you for a moment grinning before speaking —"Long time no see!"