These past couple of chapters, particularly this chapter with how Izumi worried that he may have missed Shikimori more than she missed him, got me thinking; Shikimori has been without Izumi, due to Izumi's illness, and she's been doing fine. Izumi wasn't even referenced by Shikimori in the last chapter. Thinking about it, I couldn't imagine the author doing the same for Izumi without having the character worry over Shikimori 24/7.
That's when I realize why certain people can't get behind this manga; Izumi has no character outside of being Shikimori's love interest.
I reread this manga up to this point, and there's not a chapter where Izumi appears in that doesn't do something that's in service to Shikimori's character, either with him doing something for Shikimori, him thinking about Shikimori, or him (and other characters) talk about how Shikimori is the greatest thing to happen to him.
Yes, you could say he's clumsy, awkward, and nice, but those are character traits you mostly see with "Mary-Sue/Gary-Stu" characters, not a good sign.
Yes, you can talk about his friends and family as well as how he got other girls to fall for him, however that's still defining a person by the people around him.
The only thing Izumi has going for him is that he's good at cooking, that's not enough to establish a character. Even then, in the same chapter where his cooking skills are established, the other characters joke that he'll cook for Shikimori everyday, making Izumi's skills something for Shikimori to enjoy, not just something that Izumi is good at.
While Shikimori has an actual character outside of her relationship, Izumi is a character primarily defined by his relationship with Shikimori and that's an issue.
This is also an issue I have with the manga that I assume this manga is trying to subvert; the shoujo manga where the girl does nothing but fawn over how great her boyfriend is and does nothing else of note in the story other than be the girlfriend. If one half of the romance is only their to be the love interest for another character, then the relationship feels one-sided, to me, and it's hard for me to get invested in the romance.
This dynamic would be fine if Shikimori and Izumi's romance was a subplot, however, if a story centers around the romance of two characters, I want to have an investment in both characters outside of the relationship.
Perhaps I'm overthinking things and people are fine with Izumi being this passive cinnamon roll that always gushes over Shikiomri.
I still like this manga, however I now realize why it hasn't really clicked with me the same way other romance manga like Lovely Complex and Ore Monogotari have; If I'm reading romance manga, I want to see two characters to fall in love, not one character gets a love interest.