Okay, Let Me Talk About These Panels For Just A Moment Because I Feel Like Their Inclusion + Removal

okay, let me talk about these panels for just a moment because I feel like their inclusion + removal is something that speaks volumes about Serizawa and Reigen's dynamic.

this, by the way, is a wonderful scene. it in itself lets Serizawa see a more vulnerable part of Reigen that he's genuinely surprised by, not only because of what he's saying, but because he's showing any vulnerability to him at all. before this, he talks about how he thinks no one would ever want to be in a relationship with him if he showed his true colors. vulnerability is something Reigen struggles with a lot, and if we think of this panel as him talking about his partnership with Serizawa, I think this implies some really important things.

first of all, it implies Reigen is powerless. here, he's indirectly confessing that he's powerless, just like Tsubomi, but still wants to support Serizawa in the same way she does with Mob, not treating him any differently just because of their powers instead of his current ordeal of exorting them for his own self gain, which is apparent by just how much he underpays him too, taking advantage of him rather than supporting him.

however, Reigen, unlike with Mob before, is seen genuinely supporting Serizawa. he encourages him to go to school, to make new friends, doesn't pressure him into the job like he's done before either. I think the rejection scene is REALLY good because not only does it show Serizawa's character development but also Reigen's. considering how he'd treated Mob in the past whenever he tried spending time outside of work, it's a development for him as well to accept that instead of trying to keep Serizawa with him.

second of all, by calling themselves partners, it means he's seeing Serizawa as an equal rather than someone below his level like he'd done with Mob before. he's not under his command, at least, not anymore. he's his own person and he's learnt from Reigen, and he's now grown as a person. he's not the same person he first hired anymore, and he's acknowledging that.

third, by saying they live without distorting each other, it means Reigen doesn't want to manipulate Serizawa in the way he did with Mob as well. Tsubomi and Mob learnt from each other as friends when they were kids, changed each other in a positive way. they both felt comfortable around each other, and Reigen is saying he wants that for them as well.

so, for this to be excluded out of the anime, what exactly would it mean if we're using this interpretation of it?

without any of this ever being said, Reigen would be disregarding the fact that they're a team, instead not wanting to admit that they're basically partners and not stooping to that level of vulnerability. it's also important that in those panels, Reigen's expression isn't shown at all, while in the anime we can see his reflection being distorted by the liquid in the tea, showing us how he sees himself as distorted. he WANTS to say what he says in the manga but doesn't, thinking that he's too distorted to ever think of being partners with someone like Serizawa.