In a surprise announcement, Japan’s blockbuster messaging service Line announced that current CEO Akira Morikawa will step down in March, passing the torch at a high point of success, expansion into promising new territory, and a likely 2015 IPO.

Morikawa will be succeeded by current COO Takeshi Idezawa, whose promotion may have been foreshadowed at Line Conference Tokyo 2014 back in October. At that event, Idezawa personally introduced the Line Pay and Line Taxi features – presenting Line as a “smartphone gateway for your life,” not a mere messaging app. Line’s push to be an all-encompassing lifestyle app, a la WeChat, is further evidenced by the official formation of the Line Music joint venture with two major record labels and the purchase of Microsoft’s streaming music service MixRadio.

Morikawa was appointed CEO of Line parent company NHN Japan – the Japanese arm of Seoul-based Naver – in 2007. He saw the service rise from a basic messenger, designed in the wake of the devastating 2011 Tohoku earthquake and tsunami, to an internationally popular service that helped usher in the “sticker” movement with characters that now star in TV shows and hit mobile games. The company’s recent expansion into payments – as well as upcoming forays into taxi hailing, manga, streaming music, home delivery, and RPG gaming – could boost its appeal far beyond simply being a convenient way to keep in touch with loved ones or kill time.

Under Morikawa’s direction, Line has amassed 560 million registered users as of October, with 170 million of them monthly active users. His legacy isn’t perfect though, as Line was embroiled in a fraud scandal last summer that cost Japanese users roughly US$1 million in damages after hackers gained access to user accounts and demanded money from individuals on their contact lists. The problem wasn’t exclusive to Japan, but it’s unclear how much money such illegal activity cost users elsewhere.

Idezawa’s promotion rests on approval from Line’s board of directors, but he will almost certainly assume the role on April 1. Morikawa will stay on as a company advisor.