This research deals with search tasks of agents, in particular, a meeting task where agents try to gather into a single location starting from distributed arrangements. The meeting task is ubiquitous in cooperation because agents need to approach one another if they wish to work together effectively. For example, in cooperative computation, multiple processes must come near in order to reduce communication cost. An efficient solution is one in which all agents work simultaneously, and in which the meeting location determines adaptively. However, the difficulty with this solution is that the agents, and hence the meeting location, will move unpredictably.