I know you said they were self-explanatory. But...do you think you could explain the appeal for you in the ships and friendships listed in the "Still Really Like" tier?
Generally, the vibe is that these are the ships that I most like for him, within the constraints that the other person has to be an Ultimate. (Since Makoto and Hajime, the non-Ultimates, are already in the highest tier.) For the most part, I like him with characters who will go against the grain of his more unsavory convictions, because the part of me that is really bothered by his thing with Ultimates wants to see him recover from it. (It's the burnt out former gifted kid in me, I think. And that hyperlink is to a song of the same name. It's a good song.) But to break it down more specifically:
Komanami: I like their interactions in the game, and since I mentioned that I'm kind of unenthusiastic to ship Nagito with any Ultimates, Chiaki is up there because, of the Ultimates, she at least would really push back against a lot of his stuff regarding talent. They both like games, they both have surface-level mellow vibes, and I love the height difference. The fact that she's willing and able to politely ask him to stop doing what he's doing is nice. And I think he's someone who would gladly just let her sleep on him.
Komazumi: Similar to Chiaki, of all the Ultimates, Mahiru is (and sees herself as) pretty normal, and she has/had a reserve course best friend. There's enough in place for her to refute some of Nagito's stuff, and she's often assertive and considerate. She thought to bring him food when he was tied up. Her comment that he would make a good stay at home dad (or whatever it was) in SDR2 also helps. And I think the fact that Mahiru is someone who will readily admit to not being okay is good for him. Also, luck and photography can be an interesting combination.
Kamukoma: This is opposite vibes from Komanami and Komazumi, but Izuru and Nagito's very similar baggage can work well in a scenario where they're both trying to heal. Or be an absolute powder keg, in a scenario where they're not. I ship them both with Makoto more, but I do still ship them with each other. Partially because there's too much good fanart of them not to. And partially because, as I've mentioned in the past, I have a personal fondness for equilateral triangles.
Nagito x Chihiro: Okay, so here the ship answers the question of "If I saw Nagito do an out-of-the-box extreme gesture of devotion for someone, which character(s) would I be cool with having on the receiving end?" and also "Which character(s) could use a slightly over-enthusiastic pep talk?" (I think Nagito would really flourish if he gave someone a pep talk and they actually brightened up and got inspired. He dreams of that kind of win.)
Like Mahiru, Chihiro will just openly not be okay. Chihiro will openly cry. Chihiro will openly ask for advice. I think those things would be good for Nagito. But also, Chihiro wants to "become stronger", and I think having someone willing to go to misguided lengths to cheer them on and help them out would be a positive thing. Nagito would love an Ultimate with a specialized intellectual talent who wants to push themself past their current limits. Would they potentially be a bad influence on each other? Yes, but in a way I'd be interested to explore.
And now for the platonic:
Sonagito: This one is mainly because Sonia is one of the characters who doesn't seem to hate him, in SDR2. Her reactions to him are very focused on what behavior of his she dislikes, not disliking him as a person. And Nagito tries to stop Teruteru from harassing her and makes fun of Kazuichi when she rejects him. They have a cute thing going on, is what I'm saying.
I think there would be more here if she were only born a princess and not also hypercompetent at being a princess, speaking a bunch of languages, etc. If it was just "She was born with her station and that's enough to call her an Ultimate," then that could begin to pull a thread, but she's just genuinely excellent, which would only reinforce his belief in the concept of Ultimates, so that's one for the minus column, lol. Don't get me wrong, I love Sonia's skills for her character; just in the context of her being friends with Nagito, it doesn't advance what I would want it to. And that's fine.
Nagito & Taka: Their diametrically opposed ideologies provide exactly what I want out of any Nagito relationship. And Nagito's very particular vibe of "regular rule breaker who is highly respectful toward authority" would be cool with Taka's very particular vibe of "wants to be friends with everyone but also no running in the halls". They both have trouble coming across how they want to, with their peers, and they both have a kind of callous way of expressing themselves sometimes, and they're both highly principled in very different ways. It'd be fun to explore a friendship between them.
Nagito & Kyoko: They're both so smart, and they have such different vibes. (This isn't an actual part of the character analysis, but I'm thinking of the Danganronpa Abridged joke/moment where Kyoko goes "No. Shut up," when Leon tries to say something during the first trial of THH, and comparing it to the canon moment where Nagito just says a knowing "I see," when Gundham says something in the fourth trial of SDR2. Does that make sense?)
They just know stuff, and they're both sitting on it, Nagito with a smile and Kyoko with a stoic expression. They could both just silently absorb and process information and both know that the other has picked up on what they have picked up on without saying a word. And then, if they're working together, both use it to corner someone verbally. And if they're no working together, then they try to work around each other mentally and that's also very fun!
Honestly, I love the idea of Nagito smiling sunnily at Kyoko and Kyoko staring stone-faced back and they are best friends, and I also love the idea of Nagito smiling sunnily at Kyoko and Kyoko staring stone-faced back and they are enemies. But it's also cool if they're not quite either one but they just have an understanding of each other that most don't have. Or if they're both dating Makoto and they just get each other in an almost kind of tense way, maybe accepting, maybe even hostile, just any angle for those two could be so cool.
