Help! The Gyaru and My Stepsister Have Both Become Yanderes

Sato Ao is a seasoned Galgame player, a master of romance in theory, and a blushing virgin in practice. He thought life would go on like this forever, until Saotome Ayano appeared. And only later did he discover... The person I'd been raising like a little brother was actually a girl. The way they looked at me also started getting stranger and stranger. “Who do you like more, her or me?” One is a domineering, brash gyaru, while the other is a stepsister hiding beneath a tomboyish exterior. Their personalities may be completely different, but they share the same goal: To keep me by their side. There are no save files, no reloading, and no walkthrough. Choose wrong and there'll be trouble. Don't choose, and there'll be trouble too. The ending of this romantic battlefield... No matter what I choose, I'm the one who ends up in trouble.