I'm assuming in the next chapter, Sumi is now aware of Mami being a maneater due to her previous encounter, and that's the reason she doubles down on her affection on Kazuya. That would make the spin-off 100% canon with the main series.
That smile seriously melted my heart but of course fucking Mami had to show up. Been a while since I've felt like this since she's been basically forgotten in the main series so she hasn't ruined anything in a while.
@Bestgirl_Ruka
That's jail time though. Now reporting them for sexual harassment (under fucking cameras!) is completely another issue. @newmangareader246
Never have understood Mami hate. It's pretty rare to see such unapologetic bitch as one of the heroines, feels fresh and unusual.
It wouldn't be exaggeration to say she is the only reason I didn't drop main series ten chapters in.