all right, I’ve made a correction taking into account your suggestions.
@tastylemon16
1. he prepares the shurikens at his fingertips, , lays himself on his feet and leans back, throws the shurikens, allowing the shurikens to gain momentum

2. in order for her to throw shurikens in different places at once, I gave her a little smoothing on the arm

3. as you said, I finished the easing before launching the shurikens, made them come out hard and continued the easing until they stuck in the mannequin