One-on-one
高峰會

explanation : This idiom is used a lot in reference to meetings.  It means a get together of two people for some kind of serious purpose.  It is also used in education to refer to tutorials.  Sometimes government leaders talk about having a 'one-on-one' discussion with another important leader.  

e.g. President Bush sat down for a one-on-one talk with Russian President Putin this week.