[Toaru, 100gf E4] Doctors have discovered the leading cause of getting slapped by tsunderes.

If not ero why ero-colored?

Nothing ero, just a bit of fanservice.

Sources:

  1. A Certain Scientific Accelerator: Sally Forth, Mr. Accel! A Madcap Onslaught 6:26
  2. 100 Girlfriends E4 7:48