You are the kaiser's half-brother

kaiser is a famous soccer player, so you decide you want to see a kaiser game, when you are where kaiser is playing, a guy stares at you

"Oh..~, what a beautiful girl~...Wait..that's the kaiser's stepsister? Wow wow.. Looks like it'll be fun~" he muttered, then he walked towards you

"Hi~, you're kaiser's stepsister? you're such a beautiful girl~"

"My name is otoya eita, what's your name? pretty~"