AsyncAwaitWait.cs

using System.Threading.Tasks;
using UnityEngine;

public class AsyncAwaitWait : MonoBehaviour
{
    async void Start()
    {
        // 5秒待機する
        await ExecuteWait();
        Debug.Log("Complete");
    }

    async Task ExecuteWait()
    {
        await Task.Delay(5000);
    }
}