The 24-year-old is set to sign for Arsenal this week on a five-year deal for a fee which could rise to 35 million pounds ($45.8 million), with head coach Arsene Wenger revealing that deals for the Germany international and Lucas Perez are almost complete.
Mustafi will join compatriots Per Mertesacker and Ozil at the London club, and said Arsenal's attractive style of play is another factor contributing to his decision.
"I did not see Per for a long time because he quit international football but I talked to Mesut," Mustafi was quoted as saying by Sky Sports on Monday.
"He told me everything I wanted to know. Everything was positive, so I was convinced very fast. It did not take much."
The 24-year-old further said, "I have always loved Arsenal, I like how they play -- it is not typical English. The game here is more like in Spain and with the German national team, keeping the ball on the grass, so it was easy to convince me."
Mustafi came through the youth systems at Hamburg and Everton before breaking into the first team at Sampdoria, and joined Valencia in 2014.
He has been capped 12 times by Germany and scored against Ukraine at Euro 2016.
Arsenal beat Watford 3-1 on Saturday to claim their first win of the EPL season, and are poised to significantly strengthen their squad before Wednesday's transfer deadline.