胸鎖 きょうさ乳突 にゅうとつ すじじゃないです
kyōsa nyū totsusujijanaidesu

Noun
Desu Copula
Negation Auxiliary

The polite negative form of 胸鎖乳突筋

1. It's not the sternocleidomastoid muscle.

Negative
Polite
Casual Register