One

"Shoto, I'm not saying stay away from her. No it's a little late for that, I'm just warning you to be careful with my sister." Katsuki's voice echos into the bathroom of Shoto's hotel room.

"I don't quite understand what you're meaning, Baku." Shoto responds, I can hear the questioning tone in his voice.

"Just remember this, Sirens in the old stories would sing to put sailors under their spell to draw them to their death. My sister wouldn't kill you but just don't break her heart, her quirk is emotion based now." Katsuki says before the door closes.

Sirens are dangerous, my brother was right to warn him.