Many times throughout the seasons they have many xana attacks and most of the time its yumi that almost falls into the digital sea and its ulrich that comes and saves her. now a lot of あなた might say thats so not even true but i am sorry to tell あなた but it is.
I believe that yumi has her good moments but then she has her bad moments when everyone is like come one yumi あなた can do better than that. Let me tell あなた something she can do better than that and she does but i don't know one episode where the group doesn't have at least one bad day. Yumi is my お気に入り and there is no changing that.