My post relating to the bi-sexuality of the Samurai was a bit bullet point, so here is more detail.
The Japanese (Edo period) did not distinguish between different types of sexuality like hetrosexual, bisexual and homosexual. These Western origin terms have no meaning to the Japanese of those era. But this is the Western definition of what was practiced. People had relationships of love and sexuality with others of the same sex. The term I have seen to describ it (I don't speak Japanese so I am quoting with faith in the source) is "nanshoku", which apparently does not translate well in to English, but is like 'manly love', 'comrade love', or 'male colours'.
A source for you is:
Cartographies of Desire: Male-Male Sexuality in Japanese Discourse, 1600-1950 - Gregory M. Pflugfelder
And a link to details:
1 quick quote from the page:
The former explores the intersections between increasing commercialisation of sex through (male and female) prostitution in the 'pleasure quarters' of urban centres, and pre-existing nodes of male-male sexual intimacy within the Buddhist monkhood and samurai. Discussion of the latter examines contemporary official strictures and regulations on sexuality (including, but not exclusively, male-male sexuality),
On other things, I did not say that Aikido (as in Uyeshiba Aikido) existed before Uyeshiba Sensei, but the word did and was used for some jutsu. There have been other threads where this has been discussed.
Other things have been stated better than I could elsewhere on this thread.