Author-baka somehow found a way to make a character even more pathetic than Kazuya... and it's one of the girls from his harem.
Sumi is capable of destroying her own mental stability for this guy, she suffered when noticed he and Chizuru were living together, she's the proof that this author isn't making a romantic comedy, but a psychologic drama about love and rejection.
And it's sad that even coming from Sumi and her well-intended and self-harming motivation, in the end she's also not helping Kazuya (and us as readers) to leave this purgatory where his (and ours) punishment is liking Chizuru.
Sumi is capable of destroying her own mental stability for this guy, she suffered when noticed he and Chizuru were living together, she's the proof that this author isn't making a romantic comedy, but a psychologic drama about love and rejection.
And it's sad that even coming from Sumi and her well-intended and self-harming motivation, in the end she's also not helping Kazuya (and us as readers) to leave this purgatory where his (and ours) punishment is liking Chizuru.