People randomly stamping (signing) my stuff

My stamps, and one day with very small remains of someone else's stamp.

At work, every day I have to go to a different building a three minutes walk away and stamp my hanko (stamps are used instead of signatures in Japan), signing that I am here today. If you stamp on a day when you are not supposed to work (say, a Saturday), it causes huge problems. The solution is either to get out a new clean stamping paper, and re-stamping the whole year up till today, or to take out a knife and scratch all the ink off. Neither solution is that tempting.

Forgetting to stamp one day that you should have stamped is also very much frowned upon, but can be solved by stamping that day later if the office people are nice to you. If you are unlucky, you end up having to write lots of papers explaining why you did not stamp that day even though you were working.

This week, someone else had stamped their stamp on my sheet. I feared this would be a huge problem, and that I would have to carve it off with a knife or possibly re-stamp every day from the beginning of April (the start of the financial year here). It turned out that since I had not actually done anything wrong myself, one of the secretaries spent yesterday with a knife, so I actually did not have to do anything at all.

The office people are usually very strict with me, and I have to do things properly or they scold me. My professor has more leniency, and he never stamps at all (instead, our secretary borrows his stamp and stamps for him). Other people are allowed to come in once per week or so and stamp all the days the have worked (but I have been told very clearly that I am not allowed to do that), which saves them some time. There are many other instances of other people meeting a fairly loose attitude, that I have never met, haha. I think it would help if they thought I did not know any Japanese.

This time it was one of my colleagues in my lab who had stamped on my sheet. He had managed to stamp: a) open the wrong sheet, b) stamp a sheet with hundreds of stamps about twice the size of his stamp (and of course very different letters), c) stamp the wrong day which was on the wrong side of the weekend "do not stamp these spots" markers, d) not notify the secretaries that anything was wrong. All in all, quite impressive, haha. But when I notified the secretaries, they seemed to be in a good mood and just said that perhaps it meant I could go home for the day and that he would do my share of the work today? They also said they would fix it and told me to come back to their building again, later the same day.