Asakusa Jinja has special goshuin for its natsumoude, shown in the photographs.
The blue one is the natsumoude goshuin, so you can get it with any date from the 1st to the 7th; the date is always the date on which you visited the jinja. You could get seven, one for every day, and I suspect that some people did. The rabbit and frog are based on the Chōjūgiga, which always sounds like a data communication standard to me, but is actually a set of scrolls, dating from the twelfth century, showing amusing animals doing human things. (In English, it is apparently called the Scrolls of Frolicking Animals.)
One notable thing about this goshuin is that there is no red on it. The “shu” refers to the traditional red colour of the seal impression, so the meaning is clearly shifting a bit with changes in practice at jinja.
The green one is the tanabata goshuin, which was only available on the seventh. (It actually has some red on it!) Since I happened to be volunteering there that day, I got both.
Traditionally, goshuin were stamped directly into your goshuinchō, or goshuin book, but during the pandemic a lot of jinja have been giving them out on paper like this. There are two benefits. First, the jinja staff do not have to handle the book, which reduces the risk of transmission that way. Second, people do not have to wait around to get their book back, which reduces crowding.
That is important. When I arrived to start volunteering, before 10 am, there was a short queue, and by the time we had finished setting up, at about half past, there were a couple of dozen people lined up to get the goshuin. That queue did not really get much shorter for the whole day. Indeed, at the end of the day a young woman asked us if she could still get a goshuin, because the website had said that they were being offered until 3 pm, but there was still a queue. (I said we didn’t know, but that she should ask the chief priest, who was standing near our booth. She did get her goshuin, and she stopped at the booth to let us know on her way out.)
Goshuin are particularly popular with women in their twenties and thirties, it seems, and in fact the jinja has a rule of only one of each goshuin per person, because otherwise they get resold online at a profit. As they are supposed to be a record of one’s visit to the jinja, that is a definite no-no.
Most jinja require an offering of ¥300 or ¥500 for a goshuin (¥500 at Asakusa Jinja), so they make good souvenirs if you are planning to visit several jinja while in Japan. They are, however, not appropriate as gifts.