It's one thing to rush towards the conclusion of the main plot, that being the relationship between Katagiri and Okada. It's another thing to cram in a whole bunch of side plots into these last two chapters.
Hattori's crush on Katagiri was only mentioned in one chapter and didn't get any more focus until this ending. It seemed too insignificant for the author to dedicate one half of the previous chapter to resolving Hattori's crush as well as this supposed rivalry he apparently had with Okada.
Sumire developing feelings for Okada only for them to be rejected in the exact same chapter it's revealed to the audience is probably the most pointless development the wrap up chapters gave us. The only purpose it served is to complete the cliched character arc of the man hating lesbian side character going from hating on all guys, particularly the male lead, and clinging to the female lead to realizing that she truly loved men, particularly either the male lead or one of his friends. It's like clockwork with these misandrist lesbian characters in manga.
Kouchiwa now realizing that she doesn't have to mentally torture "fix" any guy she thinks is a degenerate because she learns the "people can also change" from Okada is rushed considering how her character was written before. Seeing Okada reject Sumire in favor of Katagiri would only convince a character like Kouchiwa that Okada has moved past judging women based on their breast size but not men as a whole and certainly not the other guy she was currently "dating". I now realize as I'm typing this that I don't think the second friend even got a name, at least to my knowledge.
Oki's whole "I may or may not be this omnipotent being whose abilities surpass all in this world" isn't really out of place considering how she's always been this sort of enigma of a character. The whole Okada would've turned into LiTeRaLlY HiTlEr unless he and Okada fell in love with each other, and I guess get married and start a family, is the part that's seems too farfetched for me to buy. I know Oki took it all back with a "Lol! JK!" but considering what Oki was capable of throughout the story, I'm inclined to believe that Oki only took back what she said for Katagiri's sake.
The author didn't even bother to wrap up the side story of Komugi mistaking Katagiri for being in love with Oki. Her last appearance was right before this 2 chapter mini arc and it was just her telling her sister to go talk to some friends for love advice. As of this point, the story ends with Komugi still thinking that her sister is a lesbian. This makes me want to see an extra chapter, either as volume extra or a twitter comic, where Katagiri brings Okada home to meet her family so that Komugi can realize how far off base she was with understanding her sister's true feeling.
Overall while I do like Okada and Katagiri, some of the side characters and plots surrounding our two leads were mostly sub-par. I do think that a sequel manga that focuses on Okada and Katagiri's life as a couple would be more interesting, and in turn have the potential to be better that this manga. However I'm not holding my breath that such manga would come to fruition, at least not in the immediate future.