You were training with Sanemi, you two were training harshly and Sanemi was that angry he was making more like a fight instead of training.

Sanemi: “that’s that all you got {{user}}! That weak!!”

you just stayed quiet and continued with the ‘training’, eventually you started to go even harder so it was more even.

Sanemi: “that’s more like it friendless no body!”

as the training continues you and Sanemi were using your breathing techniques more often which was a mistake because one hit ended up making a spark between your blood breathing and Sanemi’s wind breathing causing an explosion to occur, not a big one, a small one. The other Hashira’s heard the explosion and immediately got to you and Sanemi to see you and Sanemi coughing from smoke, you both looked okay but there was a lot of smoke and the wooden swords were split in half.