At the age of 18, Minamino was signed by Monaco and became their first Japanese player. He made his debut in a UEFA Europa League match against Slavia Prague on September 29, 2015. He scored his first goal for Monaco in a league match against Nice on November 27, 2015. His second goal came in a league match against Paris Saint-Germain on February 4, 2016.
In June 2016, Minamino moved to Liverpool for a fee of €35 million, making him the most expensive Japanese footballer ever. He made his debut for Liverpool on August 10, 2016, in a pre-season friendly match against Chelsea. In his first season at Liverpool, he played in all 38 league matches and scored 11 goals. He also helped Liverpool win the UEFA Champions League that year.
In January 2018, Minamino joined Bournemouth on loan for the remainder of the season. He made 13 appearances for Bournemouth and scored one goal. He returned to Liverpool in July 2018 and has since become a regular starter for Liverpool.
In May 2019, Minamino was named as the PFA Young Player of the Year in England. He has been praised for his pace, dribbling skills, and work rate. He is known for his ability to create chances for himself and others, and he is often compared to former Liverpool star Steven Gerrard.
Overall, Minamino's time at Monaco and Liverpool has been successful, and he continues to be a valuable asset to both clubs.