The wavy line cancellations shown are cancellations for postpaid mail (described as "Cancellations for Postpaid Mail (JCP)" in "Handbook of Japanese Postmarks", JPS, 2008, pp.172-173). These cancels are for obliterating stamps used for payment of postpaid mail fee; the stamps are usually affixed onto a paper in full sheet, so these cancels (roller type) were introduced to quickly (and effectively) obliterate the stamps. The 3 yen sheet shown by rod222 is a very nice example of such usage.
There are several types, including
1) wavy lines only (1963-1979)
2) wavy lines with P.O. name (1979-1985),
3) line with P.O. name and date (1985-) and
4) machine wave cancel (wavy lines + P.O. + date) (1987-) .
Trainwreck's observation that the stamps look too "nice" is correct; they didn't go through the mail delivery system.
I have identified several type 2 (i.e. with P.O. name inscriptions) in your uploaded stamps;
As for the "remainders", I believe they do not exist in Japanese postal system, so if you run into a large block or sheet with the wavy lines, they're definitely for the postpaid mail payments.
Hope this helps.