The greatest success of Yellow Tears is its authentic depiction of Japan during the 1960s. Comparing to some other movies on the same era, Yellow Tears does not devote excessive effort on recreating sceneries and Tokyo landmarks as they were the 60s; instead, it focuses on creating the atmosphere, and thus presenting the spirit of the era.
We can find numerous historical references in the movie: the construction of Shinkansen, the Tokyo Olympics, Pachinko house playing the Fleet March, Shinjuku train station full of people lying on the floor waiting for departure trains (an interesting comparison with the ultra-modern Shinkansen-Densha-Subway hub structure today) and many others. On these details the movie truly catches the taste of post-war Japan, with its full throttle economic expansion, also the resulting prosperity and social displacement. The movie would be particularly interesting to watch if the viewer is familiar with the history of the period.
In the film the four main characters are very properly the symbol of young dreams prompted by the social developments- a writer, a singer, a painter and a manga author. They desire to pursue their dreams without having to "sell themselves to other people", or resort to employment (no doubt a touch of liberalism here). For these young people, it is a matter of freedom-freedom to do what one like to do. This kind of thinking, though incompatible with many aspects of the social reality, was prevalent amongst young people then.
In the movie, all of their dreams except that of the manga author's ended in failure. At the end of the movie, they all settled for a stable job and "selling themselves". The best depiction of this dream lost might be the 30 second radio performance (during a vocal contest) of the singer at the end of the movie. However, what the movie is trying to emphasize is not the cruelness of this "Summer dream lost", but more on the bright side of humanity revealed during this process.
Overall, Yellow Tears is a light hearted film with a very carefully presented recreation of Japanese society in the 1960s. It is a mixture of rational idealism, realistic attitude toward life and nostalgism. When the middle-aged bar owner nods his head to "I Got Rhythm", I realized that this movie captures some essence of a time lost.