I My Me! Strawberry Eggs

Hibiki Amawa is an enthusiastic young man whose dream career is to be a professional teacher, having graduated from college with a certificate in athletics. When he is unable to pay his landlady, Lulu Sanjo, the monthly rent for his apartment, he rushes off to the nearby (fictional) Seito Sannomiya Private School to apply for a position that is open, but is summarily denied employment because of his gender. Offended, and more determined than ever to have his way, Hibiki vows to demonstrate the merits of his educational philosophy to his detractors, and with offered help from Lulu, agrees to disguise himself by cross-dressing in order to deceive the school's female-only administration. With assistance from some gadgets Lulu engineered for this purpose, he disguises himself very convincingly. Following an initial demonstration of his merits as an educator, he is hired.

Unfortunately for Hibiki, however, life as a gym teacher at this school does not go completely smoothly. With interpersonal conflicts among students causing fights and occasional mild missteps endangering his disguise, Hibiki must not only mediate his class, but also keep up appearances and navigate life in disguise.

(Source: Wikipedia)