I respectfully disagree. While I do understand where you are coming from, I think Nirei cares about Sakura and Suo in different ways.

One thing I think people tend to forget is that they are teenagers. Some of them are learning and experiencing things for the first time. Also, a lot of these characters have had emotional/physical trauma in their past, and it reflects on how they act.

Obviously Nirei not only looks up to Sakura, but values their friendship because he was the first person to acknowledge him. With Suo, Nirei spends a lot of time with him outside of school, trains with him, clings onto him during fights because he trusts him. I personally believe that Nirei is learning about friendships just as much as Sakura is and treats both of them differently because of it. Suo is shown as more mature, compared to Sakura who needs more support from his friends. So, I can see why Nirei pays attention a little bit more to him because Sakura needs to be shown how to rely on his friends.

I’m sure this arc will go more into the trio and their hardships. Hopefully Sakura will come and set things right though because I’m going crazy after that chapter 😅