Endo is the director of a commercial featuring Ren Tsuruga.
Endo meets with Yashiro and Ren just after their drive-by encounter with Sho and Kyoko in the parking garage. Ren doesn't completely keep his cool and isn't able to fully put on the Ren Tsuruga persona. Director Endo notices this and it is commented upon to Yashiro the next day after Ren behaves like his usual self again.
Yashiro apologizes, but Endo (is or and his assistant are) actually delighted to have caught a glimpse of the real man behind the actor. Endo guesses that Ren was a bad boy in his younger days (as relayed by his assistant).
Endo (or his assistant) praises Ren's performance as Katsuki and anticipates Ren playing darker roles moving forward.