Friendship already started going down the drain once the uke developed romantic intentions. Once its reciprocated, it will be completely gone from both sides.
You can be sexually attracted to someone, even be sexually involved with them, and still be capable of being a friend. But, if you have developed "romantic" inclinations for a friend, you have ended friendship from your side. You are now courting them.
After all, if you could still be considered their friend, you wouldn't be seeking to own them. You wouldn't desire to make them dependent on you. A friend would feel threatened by a friend's other social relationships only if they felt insecure about the friendship in the place or when they actually felt neglected as a result of those other relationships. But, unlike a romantic suitor, a friend doesn't dread the very idea of their friend having other friends, just because. In fact, friends probably get more insecure at the prospect of their buddy getting into a romantic relationship if buddy is the "hoes before bros" kind of a person. But, a "bros before hoes" adherent gains wingmen when they seek out a romantic relationship.
A friend doesn't seek to supplant your family as the core of your life but they synergistically work to supplement the role of your family. Someone with a romantic motivation, however, chafes at the idea of not being at the centre of their target's life, of the target having more important relationships than themselves. If you removed the desire to own a person from the concept of romantic attraction, the concept itself would stop existing.
Because, the doctrine of "romance", more technically called "courtship" is fully derived from mate acquisition and mate control impulses. It is a social interaction that is fundamentally about improving one's own reproductive success while reducing competition and lowering one's parenting burden. If, whatever you think a perfect romantic relationship is supposed to be beyond the sexual aspect, had all its mate control aspects removed, it would just turn into your normal, platonic familial and friendship relationships.
Its sad that it happened like this.. but in a good way, I hope both of them will take some time and to come with terms on how they truly feel.. the usual.. misunderstanding, miscommunication and everything fails.. They are worried that the friendship will just go down the drain.. I just hope that everything will be okay for both of them and have the courage to confess and accept.. honesty guys please... ╥﹏╥ Hoping for the next update please... Thank you so much to our dear uploader-san and translator-san! ^_^