Himeko saves a first-year student, Jin, from some punks, and he falls head over heels for her. In order to get him to stop hounding her, Himeko tells Jin that she's already got a boyfriend... Bossun! Now all she has to do is prove it to him...
Himeko, your expression is too stiff.
Himeko, tienes la cara nerviosa.
Himeko, tienes una expresión muy rígida.
Himeko, sua expressão 
está rígida demais.