Man, I dislike both of them quite a lot. Rin's indecisiveness and her shell are kinda annoying and would be a handful to deal with, but Momoka should have been aware of that before she started her little game. Her attitude towards Momka after the fight is kinda impossible to gloss over since she obviously takes their relationship for granted.
But Momoka is on another level. She should know that if she wants to build an actual relationship with Rin, it needs to be slow and steady. Instead, she tries to push the physical aspect, almost completely ignoring the need for trust and emotional closeness to be there for it to work. Thus she creates a superficial relationship with her own hands and then gets pissed when the other party calls it superficial. Following, she immediately jumps ship and intentionally does the most hurtful thing she can, expecting... not sure what exactly?
Character likability is like 4/10 for Rin and 1/10 for Momoka in my book.
Still curious where it will end up though, so waiting for new chapters.