TOKYO — Eiko Moori, a 24-year-old office worker, felt the pull of manga one day when she saw an ad on her mobile phone screen. Because she grew up on a steady diet of manga, a form of Japanese cartoon, the offer to view “Mischievous Kiss,” a comic love story she was devoted to as a teenager, for just a few dimes an episode was irresistible. She took the plunge: For a total of ¥1,600, or about $17,