Sorry, this is not about the kanji, but Aikido is a well-known martial art with certain image, "anybody welcomes the young/old/male/female".
It must be just something like a rumor but the real aikido training where the young and strong J riot police takes is so hard that they even vomit after it.
If you have a chance, the US-J exchange program or something, please try it and share your experience for your 2nd-dan. No picture is needed.
From a Judo lover