The extras weren't translated when I first read the main story. I just happened to have a spontaneous look here only to see the comments mention the extras. I was a bit apprehensive going in as some claim that Nishizaki was OOC and mellowed out too quickly and abrupt, but having read the extras now I can firmly say that's just not true. A constant in Nishizaki's characterization is his pride born from what happened with his family. His uncle and aunt never cared for him, their wealth was never his. He spent most of his life as a "charity case" (in his eyes) and had to pay dearly for it. With his life going to hell in a handbasket so quickly after high school, he had very little time to grow past his adolescent ways. Everything that happened in the extras was to give him the space he needed to find himself, the person who he is beneath the layers of spikes and bristles. With the discipline and rough love Nagano gave him, along with other stable relationships as well as the solving of the yakuza ties, Nishizaki didn't need to be on the defense all the time. This isn't a new aspect in Konohara's stories. There have been lots of characters who change for the worse when life becomes precarious, loss of work, home, family, they hit bottom to various degrees, and can't become better versions of themselves until their basic needs are met. Nishizaki falls under that category of character, and I think his arc was done justice with the space it was given.

That aside, the extras had me weeping with how utterly sweet it became when Nishizaki and Nagano found the courage to be happy together. My heart clenched at first with their trip to Nagano's mother's place. I never thought they'd get to where they got. The ending of their story, as far as we get to follow them, is one they deserve and one I enjoyed reading.