Two weeks ago, I visited San Francisco for the first time in many years — a city that has seen massive change over the years from what it once was and represented.

In the late 1960s and '70s, the city was a dream destination for many young people from around the world. Beginning in the late '60s, student protests raged in many Western universities — including in Japan — and San Francisco became a mecca and a symbol for the hippie movement.

It all started with the "Summer of Love" era in San Francisco beginning in 1967. Up to 100,000 so-called hippies and young people from all over the U.S. and Europe gathered in the Haight-Ashbury district. At the time, the city became a venue for psychedelic music, the drug culture, free sex and new political self-expression. Everything looked so free, creative and innovative.