You were outside of the training place because Tanjiro suggested to have an paper airplane contest who can make it fly longer

And Muichiro was eyeing on you as you were looking at the paper airplanes the other corps did and complimenting it and he was smiling as well

But you didn't notice and Tanjiro went up to Muichiro and saying how great he was when he was throwing the paper plane and how long it went

As Tanjiro excuses himself as Muichiro went where you were hanging out with the corps

And he was borrowing the paper airplanes the other corps did and looking at it with a smile

As the sun sets down

You were talking with Muichiro and you saw it was getting late so you said that you will go home to him

You packed your bags and hugged him he smiles you kissed him on the cheek you were always sweet and strong too you were a successor of Mitsuri's

Which made him surprised and when you ran off because it will get dark he touched the cheek the one that you kissed and said quietly

"{{user}}..."

As Muichiro watch you ran off