[C-2909] Married woman consultation [007]

Yup – serial number, like seventh in the series

Look at the spine of the cover. See the 00七 ?

七 shich/nana Seven

As in

  1 一 (ichi)
  2 二 (ni)
  3 三 (san)
  4 四 (shi/yon)
  5 五 (go)
  6 六 (roku)
  7 七 (shichi/nana)

Next in the series will likely be

 8 八 (hachi)

Or in the serial style of the series’ covers

00八