According to the latest smartphone market share report on a country level in Q2 2017, published under Handset Country Share Tracker (HCST) service, Samsung posted the biggest share in Japan smartphone market in 4 years.

Samsung had enjoyed over 10% share in Japan smartphone market by mid of 2013, but kept losing the market share since then, squeezed by Apple and local vendors, but Q2 2017 saw stronger performance of this world's largest smartphone vendor, mostly based on stronger performance of its flagship devices, such as S7 edge and S8 devices.

The in-detail smartphone market volume and share by vendor by country can be viewed at this link.