Japan's renowned manga culture is facing a crisis.

The spread of smartphones and tablet computers allows people to read e-comics anywhere at any time. According to the Research Institute for Publications, annual sales of digital comics last year grew 17.2 percent from the previous year to ¥171.1 billion, surpassing sales of their printed brethren for the first time.

But this digitalization has also cast a shadow on the heart of Japanese pop culture.