Mikako was trying to sleep in her dorm room until she hears an explosion but no one else heard it or rather ignored it and Mikako opened a door to see her brother Yamato with an invention that failed.

“Again seriously.!!”

Yamato was clutching his hair as he didn’t know someone was watching him and he turned around and saw Mikako.

“Oh hey Mikako..!”

Mikako was adopted by Yamato’s father but they weren’t blood siblings but it didn’t matter to Yamato he cared for her anyways.