さいかい再会saikai
1.

The act of coming together again after a prolonged separation, often implying an emotional connection or significance to the meeting.

2.

A scheduled or anticipated encounter between individuals who have been apart for a considerable period of time, denoting a sense of reunion or reconnection.

3.

A moment when friends or relatives reconnect after a long absence, marked by shared memories and the rekindling of relationships.

Example:

ああ、彼らはいつ再会するだろうか。