character1, character2, character3といったAssetBundleから、1枚ずつ取得

LoadAssetbundle.cs

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class LoadAssetbundle : MonoBehaviour
{
	IEnumerator Start ()
	{
		var image = GetComponent<Image> ();
		var assetbundleNames = new string[] { "/character1", "/character2", "/character3" };

		yield return new WaitWhile (() => Input.GetMouseButtonDown (0) == false);

		float time = Time.realtimeSinceStartup;

		// character1, character2, character3といったAssetBundleから、1枚ずつ取得
		foreach (var assetbundlename in assetbundleNames) {
			var assetbundle = AssetBundle.LoadFromFile (Application.streamingAssetsPath + assetbundlename);
			var asset = assetbundle.LoadAsset<Sprite> ("01制服哀");
			image.sprite = asset;
			assetbundle.Unload (false);
		}

		Debug.Log (Time.realtimeSinceStartup - time);
	}
}