You could start with a vivid description of the characters' separate lives and how they've been yearning for this meeting. Also, throw in some obstacles to heighten the drama. Make the actual meeting emotionally charged and fulfilling.
Start by creating anticipation. Build up the characters' longing and the significance of the meeting. Make the reader feel the tension.
First, establish the background and reasons for the long wait. Then, focus on the characters' emotions and expectations. Add some unexpected elements to keep it interesting.