One reason I like this manga is the fact that Tamaru-sensei was either a fencer or kendoka or did a lot of research. The lunge stance demonstrated by Chika here is pretty much exactly how we did it in practice without a weapon and her form is pretty good for a novice – her hand should be level with the shoulder and the leading knee directly over the heel, but as Miki notes approvingly, she lands flat on the front foot, so her center of gravity is balanced between her hips. It’s typical to throw the front foot forward and slide it on landing, which is a no-no because it means your recovery, either forward or backward is delayed because you are off-balance. As in any martial art, control of the engagement distance is critical, who controls the distance controls the initiative, so being able to change direction quickly is key.