"When I knew I was coming to Arsenal, I immediately thought of the French guys who play here," Pepe said. "I thought of Ozil, the world champions, Lacazette, Aubameyang and many more.
"These are the players who sprang to mind because I used to watch them when I was at Lille. Also, Lacazette used to play for Lyon, so I had the opportunity to play against him."
Pepe can operate on either wing but usually plays on the right, where he can use his speed to cut inside on to his favoured left foot. He scored 22 goals in Ligue 1 last season and was behind only Paris Saint-Germain's Kylian Mbappe in combined assists and goals in the French top division.
"Signing a top-class winger has been one of our key objectives in this transfer window and I'm delighted he's joining," said Emery. "He will add pace, power and creativity, with the aim of bringing more goals."
Pepe grew up west of Paris and played as a goalkeeper until he was 14.
"Being here is very emotional," he said. "I have come a long way and struggled a lot, so signing for this great club is a big reward."
The fee for Pepe will be paid in instalments by Arsenal, who found Crystal Palace much less open to such a payment structure when they bid for Wilfried Zaha this off-season.
The winger becomes Arsenal's fourth signing of the off-season after Brazilian teenager Gabriel Martinelli, Real Madrid midfielder Dani Ceballos (on loan) and Saint-Etienne defender William Saliba, who has been loaned back to France for the season.