The 28-year-old will spend the duration of the 2020/21 season at the Ipurua Municipal Stadium, where Eibar kicked off the new La Liga campaign with a goalless draw against Celta Vigo on Saturday.

Muto arrived on Tyneside from German club Mainz in summer 2018 and has made 28 appearances in all competitions.

The Japan international has registered two goals for the Magpies, scoring in a Premier League defeat at Manchester United in October 2018 and a Carabao Cup tie with Leicester City in August 2019.