Measuring Day

In a lot of manga and anime series that take place at a high school, there is at least one episode or volume in which the students get a full physical examination. This usually takes place during the course of a whole day and is either used for fanservice or for lots of jokes in which certain physical quantities of (female) students get compared--or where one of the girls gets a chance to really freak out about her weight problem, imagined or not. Not to mention the usual group of guys that always try to peek on the examination.

Examples:

Doki Doki School Hours
Azumanga Daioh. Surprisingly, Kimura-sensei is almost entirely absent from those scenes, despite being an obvious avenue for cheap humor. (He shows up for a single punchline.)
Ryofukochan (where it's mostly about the protagonist's height)
Maburaho
High School Girls
Briefly in Mahou Sensei Negima
Ouran High School Host Club, complete with a mad scramble to conceal the (female) protagonist's actual gender that culminates in the Ohtori family ordering a doctor "in the next room" to keep her secret.
- The Fan Service part gets lampshaded since (barring Haruhi) all the students have their own personal doctors and the examination is "really popular" because of Mr. Fanservice.
The Katamari Damacy series sometimes has scenes like this in its outdoor levels.
Pretty Face has one of these with the protagonist trying wacky schemes to get out of the physical examination, which would reveal that he's not actually a girl. Turns out the doctor giving the examinations is the same one that gave him a girl's face in the first place.
Da Capo Second Season
School Rumble. Both Tenma and Harima sneak in as personnel, and Hilarity Ensues.
- And the actual measuring had been cancelled.
Seen as a short intro segment in Sayonara Zetsubou Sensei with Maria messing with the other girls' weightings.
The Korean horror movie, Memento Mori has a scene with this.
Lucky Star. Only one of the girls has nothing to be gloomy about, and gets flat-out scolded for it. (Though the others' complaints are hardly earth-shattering stuff: "I'm still short," "I forgot it's measuring day today and wore my printed pants" and "I gained one pound.")
Rosario to Vampire Capu2. Mizore doesn't actually get measured because she's too busy stalking Tsukune again.
Hell Teacher Nube, where the doctor is actually Nube's rival (and enemy at the time) Tamamo. When he tries to confront him mid-examination, the girls toss Nube out and call him a pervert.
Maria Holic, where a main character has to resort to subterfuge to keep his crossdressing secret.
Hidamari Sketch has an entire chapter on this. If Yuno, who cared more about her height than weight, decided not to have breakfast, then Hiro... Also, is a 2mm difference in height merely due to error?
Cromartie High School has a hilarious skit involving a visiting doctor and his reactions when measuring the less... ordinary students of Cromartie.
Variant crops up in To Aru Kagaku no Railgun. It's called "Measuring Day" but rather than a physical exam its measuring the students' special powers. Special precautions have to be taken at Tokiwadai when measuring Mikoto's Railgun, including using the pool as a shock absorber.
Measuring day presents a real problem for Makoto in Boku no Futatsu no Tsubasa: Namely, concealing the fact that she's a true Hermaphrodite from her peers.
The grade-school girls in Kodomo No Jikan convince their teacher to be measured also. Then their male teacher walks in.
Seikon no Qwaser has this for a filler episode, with the expected focus on breast measurement.
Used as a conflict point in Strawberry Eggs in which crossdressing teacher Hibiki is at a loss on how to prevent his status as male from being known after the faculty declares he must undergo a physical as well. His landlady saves the day.
Mayo Chiki
Guyver, in the 2005 anime. Gives Sho an Oh Crap moment, because at this point, he had no idea what the Guyver was, only that it had implanted something in his back the first time he wore it.