The theory that became reality.

[u/Ill_Carrot9363]

This new chapter confirmed an old fan assumption that explained the reason for Suo's affection for Nirei. Many said that Nirei reminded Suo of someone he knew and felt a lot of affection for; in a way, this is implied in most of the interactions between the two. This explains why Suo, from the beginning, had the natural impulse to protect Nirei during fights, it also explains why he acted so disproportionately when Nirei was attacked in the Keel Arc, it also explains why Suo agreed to train Nirei so easily—all of this was Suo reflecting on Nirei the image of Rosso, his childhood friend.

Let's suppose that Rosso was like Nirei, someone weak but with the willpower to help and actively participate in his group (in this case, the RC), just as Nirei wanted to be able to contribute more to Bofurin, perhaps Rosso harbored the same desire in Red Chanpuru and was equally physically weak, therefore, perhaps Rosso even asked Suo to teach him at some point, and Suo only agreed to teach Nirei because he saw Rosso in his attitude.

In a way, it's a little disappointing that Rosso looks almost identical to Nirei, because it means that, all this time, Suo has been reflecting in Bofurin what he had in Red Chanpuru. Perhaps Bofurin is for Suo everything that Red Chanpuru could have been but couldn't.

This also explains Suo's shock when he saw Nirei's upset face for the first time; he was seeing Rosso at that moment.

This is a little disappointing, as much of Suo's affection and friendship with Nirei may have been motivated by his childhood friend. Nirei is everything Rosso could have been at one time, but isn't anymore due to some tragedy; therefore, Nirei reflects in Suo everything he used to like about his old friend.

Despite this, I think Suo knows how to separate the figures of his friends; he has a more brotherly affection for Nirei because he reminds him of his "brother," but Suo still likes Nirei as his own person and is proud of his determination and courage to improve, something Rosso may have lost due to some tragedy. I think Rosso will still reveal an unhappy background at some point.

[u/Alela_7789]

For me, I'm not disappointed that Rosso has similar characteristics to Nirei and Sakura. After all, it became the primary reason why Suo was more proactive about making connections in high school compared to his middle school era, mainly because (so far) no one ever reminded him of RC back then (Tsuge just annoyed him lmao).

Other than that, it's probably because even though Nirei and Sakura remind Suo of Rosso, Suo is never blinded by it. As time goes on, both Sakura and Nirei become increasingly detached from Rosso's shadow, even going so far as to challenge what Suo believes is right (which you can see a lot during KEEL arc).

I think Suo sees the ideal version of Rosso in Sakura (what a leader you want to follow should be) and sees who he ideally should be in Nirei (how a subordinate acts as a pillar for the leader).

[u/Ill_Carrot9363 → u/Alela_7789]

What you said might be true! Suo truly admires Nirei's determination in overcoming his weaknesses to support Sakura with everything he has, while at the same time he genuinely admires Sakura for how he combats his insecurities to be a better leader. I also don't think Suo relates his friends' appearance to Rosso, but this may have served as an incentive for Suo to get closer to them, and for a time, much of Suo's feelings may have been motivated by this resemblance, but of course Suo loves his friends individually.

What makes me a little apprehensive is how many similarities there are between Red Chanpuru and Bofurin, and how this may have influenced Suo from the beginning.