Comiket ads for highly popular Blue Archive have covered up the cleavage and visible sideboobs of its female characters.
Artwork of female characters were placed on the advertisements, and the inclusion of each characters’ name on the art was used to cover up their cleavage or sideboobs.
Allegedly, this wasn’t the first time publisher Yostar did this, as they’ve been accused of doing this in previous Comikets. Whether or not this was demanded by Comiket or a decision made solely by the publisher wasn’t confirmed.
Here’s a bunch of examples of the covered up illustrations, along with some of the original artwork for comparison: