If you look at the walls of the bar Meal of Duty in Togainu no Chi - Lost Blood -, you might notice a small photo of a boy in a sailor suit. This innocuous detail may just seem like set dressing, but it's actually a nod to the real-life person who inspired much of the bishonen genre.
Death in Venice is a 1971 film about a man who develops a fixation on an adolescent named Tadzio, played by actor Björn Andrésen. Following its release, he was thrust into international fame, with Wikipedia describing it in the following terms:
After the release of Death in Venice, Andrésen spent an extended period of time in Japan and appeared in a number of television commercials and also recorded several pop songs. Andrésen has had a strong liking for Japan since then and has visited the country again over the years. Björn Andrésen's arrival in Tokyo has been described as being similar to the Beatles landing in the U.S. The young actor was met with mass hysteria and received an enormous amount of female attention.
Among those Japanese fans were a number of influential mangaka, such as Rose of Versailles creator Riyoko Ikeda, who created a portrait of Andrésen. Ikeda's character Lady Oscar, a famous example of the bishonen aesthetic despite being female, was modeled after Andrésen.
Another extremely important character in the history of both bishonen and boys love is Gilbert Cocteau of Kaze to Ki no Uta, also known as The Song of Wind and Trees. The Song of Wind and Trees by Keiko Takemiya is one of the seminal shoujo manga titles of the 1970s, one of the earliest male/male romance manga stories created by women for a primarily female audience. Gilbert's appearance was influenced by Björn Andrésen's look in Death in Venice.
These two incredibly pivotal bishonen characters then paved the way for many who came after, such as Griffith from Berserk and the many teen male characters of manga circle CLAMP.
An entire genre of character stems from a single actor in a single role. So, apart from the more general cultural influence on the boys love genre being acknowledged, what are we to make of the reference appearing in Togainu no Chi?
To quote the Wikipedia article on bishonen:
Ian Buruma, writing in 1984, considered the "bishonen in distress" to be a recurring motif in popular manga. The bishōnen in distress is always rescued by an older, protective, mentor. This scenario has an "unmistakably homoerotic" atmosphere. He also notes that bishōnen must either grow up, or die beautifully. He considers the "worship" of the bishōnen to be the same as that of the sakura, and notes that "death is the only pure and thus fitting end to the perfection of youth."
"Either grow up, or die beautifully" most closely adheres to the possible endings for Rin, who like Björn Andrésen, Lady Oscar, and Gilbert Cocteau has blonde hair and blue eyes.
Though the ages of the characters in Togainu no Chi are never stated, it's easy to infer from their relative stature – and Rin's growth spurt, should he survive – that Akira is older than Rin, and the scenes in which Akira rescues and protects Rin are, undoubtedly, "unmistakably homoerotic", such as when Akira feeds Rin water mouth-to-mouth.
Whether this parallel was intended by the creators of Togainu no Chi is unknown, but whether a specific reference or a more general nod to the role Björn Andrésen played in the evolution of bishonen, the photo in Meal of Duty serves to tie Togainu no Chi into the broader history of boys love.