One thing you can do with them is use one or more of them right before burning 10 others if it isn't going to get the target girl to a new level. This lets you get 11, 12, or 13 manyus worth of XP at the same price each.
One thing you can do with them is use one or more of them right before burning 10 others if it isn't going to get the target girl to a new level. This lets you get 11, 12, or 13 manyus worth of XP at the same price each.