While it's not on topic as far as Aikido is concerned, from an historic aspect this may be a humorous anecdote, and it happened under friendly circumstances between friends a very long time ago.
Yoshishige Okai received Menkyo Shihan in Hakkoryu in the 1950's. He took his family to Brazil, and later Portugal, where their dojo is today. Here's what I have to quote thanks to him:
We left the deep jungle of Brazil after cultivating the land for a year and then moved to the city of Sao Paulo, Brazil. I entered Miguel Couto Massage School and passed Brazil's national certification exams. Happily, I started to work as a licensed massage practitioner at Sao Paulo. After few years later, I moved to Rio de Janeiro, Brazil and met a judo athlete. He introduced me to Helio Gracie, of the famous Gracie Jiu-jitsu style. Helio told me all kinds of interesting stories and I had a great time with him. Helio told me that his best Waza (technique) is "Dojime" (scissor lock) and nobody ever countered this technique. He asked me "how would you counter "Dojime" using Hakkoryu Jujutsu?" In saying this, he immediately tried to give me "Dojime". I was telling myself that Hakkoryu is self defense. Well, I have two choices. One is "Metsubushi" (eye closer) and another one is "groin kick". In a moment of inspiration, I gave him "groin kick". Of course not too hard, I gave him a break...but I have never forgotten the surprised expression on his face and how his eyes rolled back. I think that I really understood the real significance of "Hakkoryu Goshin Jujutsu" at that moment.