To me this ending seems like the worst possible ending. Triggering some weird memories, leaving a bad taste.
For me, this ending doesn't give any hope for 'yuri wins' solution. But you know who is left with that hope? The mc, Arisa. For me it's rather clear that Fuwako came back to fight for friendship, but only for a friendship. But actually it's rather egoistic act. Arisa will continue to suffer and won't be able to let those feelings go, how the heck is she going to move on. Fuwako on the other hand will be in pretty neat position. She can keep her friendship (by hurting the other side) and a relationship. As hard as it may be, the best what Fuwako could have done, was backing off, really...