Since its messaging app debuted in June 2011, Line Corp. has shaken up the online communications landscape in Japan and morphed into a player in smartphone communications infrastructure.

But the smartphone won't last forever in the fast-changing information technology industry. So Line is planting the seeds of success for what it thinks will be the next big thing: voice-based "AI agents."

While this artificial-intelligence quest will pit the smaller Line against IT powerhouses Google, Apple and Amazon, among others, Line CEO Takeshi Idezawa likes his chances.