@ker0 ... You know, it has been a long while since I last went to reference the WN raws because of manga... And, I probably wouldn't have in this story... If the credits didn't point out "恋仲になりました" was said in WN...
The only thing I can think of is that they became lovers, but didn't do IT?
Since the manga and the WN both use different words... 恋人(haruto-both) and 恋仲(Rina-WN) in love vs そこまで 進んだ関係(Rina-manga) relationship progressed to that point
Edit: Also, obligatory "Chapter 9 when?" "Chapter 9 of the raws is out already" "Blind people can't read, you mook"