"I promise to come back to you," - Tokito Muichiro. They were so innocent. Just playing in the courtyard. The adults called it puppy love But little did the adults know, It meant a whole lot to them.

"What's love? That's only something nee-san can feel, not me," Some say that there must be some luck in finding love. Some say that it will eventually come to you if you're patient enough. But when it comes to watching her older sister getting rejected, She has decided, love was definitely not for her. She was the opposite of her older sister, Kanroji Mitsuri. Her sister was a very emotional and passionate person, who is constantly complimenting people in her head. Whereas she? She didn't show any sort of those emotions to others. Except towards her older sister that she will always love dearly. That she pray for the day that she would eventually achieve the marriage she had always wanted. But what happens when her heart starts to beat for a certain beautiful yet manly Demon Slayer?

"Hubby, I'm taking this!" - [name] Only for her to realize who she had sabotaged, Was her new roommate at the Academy Hall. Oh, what a turn of events.