phrases describing person in charge

Mastermind (noun)

Creator

“Higuchi-san is the mastermind behind the new finance services division at the bank.”

Note: Also used as a verb: “Rieko-san masterminded the buyout of the insurance company.”

Brains behind

Actual creator, perhaps unknown to others

“Teguchi-san took credit for creating the successful marketing campaign but his assistant, Miura-san, was the real brains behind it.”

Front man

The spokesman or representative of a company or organization

“Doi-san will be an excellent front man because he really know how to relate with the public.”

Man behind the curtain

Person that is secretly in charge, (from the movie, The Wizard of Oz)

“Try to avoid the front man and negotiate directly with the man behind the curtain, Kato-san.”

Behind the scenes

The action backstage (phrase from the theater)

“Most of the negotiations have already taken place behind the scenes so today’s meeting is largely ceremonial.”