Dokkiri Doctor(1998)

Haruka Nishikikoji is an overweight doctor that never seems to attract any girls. Fate finds a way as he lands a job as a doctor in an elementary school, wherein his workplace can be found on top of the schools' roof and the actual clinic looks like a medieval castle. Just when everything seems to go downhill, a surprise came one day, her first love Koizumi Miyuki, applies as her soon to be nurse.