I'm the Villainess, So I'm Taming the Final Boss, Vol. 2 LN

Eileen is racing against the clock to get to the bottom of the demonuprising for her
fianc- the demon king Claude. Her search takes herto Milcetta Academy, the setting
of the second entry of the otome gameseries...except she can only infiltrate by crossdressing?! She better figuresomething out soon because if she
doesn''t, Claude is doomed!