Japan's Rakuten is joining e-commerce giants Amazon and Alibaba with a foray into drones. The Tokyo-based company, Japan's largest online commerce firm, this week revealed its investment in a drone maker and plans to begin field trials in a unlucky setting… the golf course.

Rakuten confirmed its participation in a new round of financing for Autonomous Control Systems Laboratory (ACSL), a Japan-based firm that develops robotics and drones for industrial purposes. ACSL span out of Chiba University in 2013, and it offers its 'Mini Surveyor' drones and related services to automate tasks like surveying, inspections, monitoring and more. (DJI, perhaps the most visible consumer company, is one of many that has moved into the lucrative industrial services space — Sony is another.)

Rakuten has taken a 20 percent stake in ACSL but the price that it paid isn't clear — the company declined to tell us when we asked. It did say, however, that the two sides will "work together while capitalizing on their respective strengths in the utilization of industrial drones, in order to deliver innovation to society with technologies and services originating in Japan."

But that first test will happen at a place that is far from an industrial setting. NHK reports that, from May, Rakuten and ACSL will pilot a service that brings refreshment, balls and more to golfers at a course in Chiba. The concept is simple: golfers can order drinks, snacks or other items via a smartphone app, with the items then sent over from the clubhouse via a drone.